css path update

src/fe/mrna/css/all.css

   position: fixed;
   left: 50%;
   top: 50%;
-  background: url(../../images/modal-bg.png) #0070a0 repeat;
+  background: url(../images/modal-bg.png) #0070a0 repeat;
   transform: translate(-50%, -50%) rotate(-45deg);
   background-size: 20em auto;
 }

src/fe/mrna/css/component/_modal.scss

         position: fixed;
         left: 50%;
         top: 50%;
-        background: url(../../images/modal-bg.png) $blue-d repeat;
+        background: url(../images/modal-bg.png) $blue-d repeat;
         transform: translate(-50%, -50%) rotate(-45deg);
         background-size: 20em auto;
     }