fixes #5188: add .google-maps class to reset responsive images on case-by-case basis

docs/assets/css/bootstrap.css

@@ -75,7 +75,8 @@ img {
   -ms-interpolation-mode: bicubic;
 }
 
-#map_canvas img {
+#map_canvas img,
+.google-maps img {
   max-width: none;
 }
 

less/reset.less

@@ -88,7 +88,8 @@ img {
 }
 
 // Prevent max-width from affecting Google Maps
-#map_canvas img {
+#map_canvas img,
+.google-maps img {
   max-width: none;
 }