limit name to the last dot instead of first

Closes #1694 (closed)

frontend-js/src/main/js/gui/AddOverlayDialog.js

@@ -142,7 +142,7 @@ AddOverlayDialog.prototype.onContentChanged = function (content) {
   } else {
     var filename = $("[name='overlay-file']", self.getElement())[0].value;
     if (filename.indexOf(".") > 0) {
-      filename = filename.substr(0, filename.indexOf("."));
+      filename = filename.substr(0, filename.lastIndexOf("."));
     }
     if (filename.lastIndexOf("\\") >= 0) {
       filename = filename.substr(filename.lastIndexOf("\\") + 1);