[FIX] fitness: prevent error on opening pricing

Currently, an error occurs when the user opens the pricing page after installing
the fitness module.

Steps to replicate:
* Install fitness
* Website > pricing

Error:
`QwebError:
Error while rendering the template:
    KeyError: 'fitness'
    Template: fitness.pricing-1
    Reference: 3772
    Path: /t/t/div/div[2]/section/div/div/div[1]/div/div[2]/a
    Element: <a t-att-href='request.env.ref(fitness.product_product_7)....
`
Root cause:
* This error appeared after PR [1], likely because the XML reference wasn’t a
  string. It should be written like in [2].

Solution:
* Use a properly formatted string reference.

[1]:
#965
[2]:
https://github.com/odoo/industry/blob/9ed468d9398dd4eab49e9549357f72e329b80b58/yoga_pilates/demo/website_view.xml#L383

sentry-6955738430

closes #1261

X-original-commit: 6b45d79
Signed-off-by: Vallaeys Valentin (vava) <[email protected]>
Signed-off-by: Anshik Gopalbhai Brahmbhatt (agbr) <[email protected]>

Author: agbr-odoo

fitness/demo/website_view.xml

@@ -268,7 +268,7 @@
                                                 </ul>
                                                 <div class="card-footer">
                                                     <p>30-day trial, satisfaction guaranteed.</p>
-                                                    <a t-att-href="request.env.ref(fitness.product_product_7).website_url" class="btn btn-primary" data-bs-original-title="">Order now</a>
+                                                    <a t-att-href="request.env.ref('fitness.product_product_7').website_url" class="btn btn-primary" data-bs-original-title="">Order now</a>
                                                 </div>
                                             </div>
                                         </div>
@@ -293,7 +293,7 @@
                                                 </ul>
                                                 <div class="card-footer">
                                                     <p>30-day trial, satisfaction guaranteed.</p>
-                                                    <a t-att-href="request.env.ref(fitness.product_product_8).website_url" class="btn btn-primary" data-bs-original-title="">Start now</a>
+                                                    <a t-att-href="request.env.ref('fitness.product_product_8').website_url" class="btn btn-primary" data-bs-original-title="">Start now</a>
                                                 </div>
                                             </div>
                                         </div>
@@ -320,7 +320,7 @@
                                                 </ul>
                                                 <div class="card-footer">
                                                     <p>30-day trial, satisfaction guaranteed.</p>
-                                                    <a t-att-href="request.env.ref(fitness.product_product_9).website_url" class="btn btn-primary" data-bs-original-title="">Join Us Now</a>
+                                                    <a t-att-href="request.env.ref('fitness.product_product_9').website_url" class="btn btn-primary" data-bs-original-title="">Join Us Now</a>
                                                 </div>
                                             </div>
                                         </div>