Added missing space char in footer (#1188)

* Added missing space char in footer

* Changed space to the expected jinja syntax

Author: nienn

sphinx_rtd_theme/footer.html

@@ -53,7 +53,7 @@
     {#- Translators: "theme" refers to a theme for Sphinx, which alters the appearance of the generated documenation #}
     <a href="https://github.com/readthedocs/sphinx_rtd_theme">{% trans %}theme{% endtrans %}</a>
     {#- Translators: this is always used as "provided by Read the Docs", and should not imply Read the Docs is an author of the generated documentation. #}
-    {%- trans %}provided by {{ readthedocs_web }}{% endtrans %}.
+    {% trans %}provided by {{ readthedocs_web }}{% endtrans %}.
   {% endif %}
 
   {%- block extrafooter %} {% endblock %}