fix broken reverted-selection

i forgot to rename a use of a variable when i renamed its def

Author: marijnh

lib/codemirror.js

@@ -300,7 +300,7 @@ var CodeMirror = (function() {
       // (and later restore it again), shouldn't be used for
       // non-movement keys.
       curKeyId = (mod ? "c" : "") + code;
-      if (sel.inverted && movementKeys.hasOwnProperty(id)) {
+      if (sel.inverted && movementKeys.hasOwnProperty(curKeyId)) {
         var range = selRange(input);
         if (range) {
           reducedSelection = {anchor: range.start};