Style the dialog for option group autosave desync

@@ -1488,6 +1488,15 @@ td.diff-left:hover, td.diff-right:hover {
     cursor: pointer;
 }
 
+[aria-labelledby="ui-dialog-title-autosave-desync-message"] .ui-dialog-buttonset {
+    width:  285px;
+    margin: auto;
+}
+
+[aria-labelledby="ui-dialog-title-autosave-desync-message"].ui-dialog .ui-dialog-buttonpane button {
+    float: none;
+}
+
 /* Hide both options for the "Enable Media Replace" plugin, since the second option mostly
    just breaks hard-coded links to files */
 label[for="replace_type_1"],
@@ -1502,7 +1511,7 @@ a, input, textarea, select {
     transition:         color 0.1s linear, background-color 0.1s linear, border-color 0.1s linear, box-shadow 0.1s linear;
 }
 
-/** General Utility Classes **/
+
 
 .left, .float-left {
     float: left;