Fix extra slash in route popover image URL

Author: nickswalker

pages/routes.html

@@ -143,7 +143,7 @@ <h1 class="visually-hidden">{{ page.title }}</h1>
       <div id="${popoverId}"
            class="route-map-popover"
            popover>
-        <img src="{{ '/img/routes/' | absolute_url }}/${route.id}.jpg"
+        <img src="{{ '/img/routes/' | absolute_url }}${route.id}.jpg"
              alt="${route.name} map"
              class="route-image"
              loading="lazy" />