[FIX] website: remove bg image support for columns in s_cover snippet

The snippet section can have a color or a background. Previous commit
added the functionnality for its innercolumn too... but having a bg
image on top of another one does not make sense, so only keep the
color option for columns.

addons/website/views/snippets.xml

@@ -659,7 +659,7 @@
     <t t-call="web_editor.snippet_options"/>
 
     <div data-js='background'
-        data-selector="section, :not(.o_gallery > .container) > .carousel, .parallax, .s_text_block_image_fw .row > div, .s_banner .carousel-content">
+        data-selector="section, :not(.o_gallery > .container) > .carousel, .parallax, .s_banner .carousel-content">
         <li class="dropdown-submenu">
             <a tabindex="-1" href="#"><i class="fa fa-picture-o"/>Background Image</a>
             <ul class="dropdown-menu">
@@ -681,7 +681,7 @@
     </div>
 
     <div data-js='background_position'
-        data-selector="section:not(.parallax), :not(.o_gallery > .container) > .carousel, .s_text_block_image_fw .row > div, .s_banner .carousel-content">
+        data-selector="section:not(.parallax), :not(.o_gallery > .container) > .carousel, .s_banner .carousel-content">
         <li class="background_position_li" data-background_position="background_position">
             <a tabindex="-1" href="#"><i class="fa fa-arrows"/>Background Image Sizing</a>
         </li>