Fixed dpi warning [Fixes #1964]

select2.css

@@ -614,15 +614,20 @@ html[dir="rtl"] .select2-search-choice-close {
     height: 100px;
     overflow: scroll;
 }
+
 /* Retina-ize icons */
 
-@media only screen and (-webkit-min-device-pixel-ratio: 1.5), only screen and (min-resolution: 144dpi)  {
-  .select2-search input, .select2-search-choice-close, .select2-container .select2-choice abbr, .select2-container .select2-choice .select2-arrow b {
-      background-image: url('select2x2.png') !important;
-      background-repeat: no-repeat !important;
-      background-size: 60px 40px !important;
-  }
-  .select2-search input {
-      background-position: 100% -21px !important;
-  }
+@media only screen and (-webkit-min-device-pixel-ratio: 1.5), only screen and (min-resolution: 2ppx)  {
+    .select2-search input,
+    .select2-search-choice-close,
+    .select2-container .select2-choice abbr,
+    .select2-container .select2-choice .select2-arrow b {
+        background-image: url('select2x2.png') !important;
+        background-repeat: no-repeat !important;
+        background-size: 60px 40px !important;
+    }
+
+    .select2-search input {
+        background-position: 100% -21px !important;
+    }
 }