better regex check

Author: Antelle

FileSaver.js

@@ -99,7 +99,7 @@ var saveAs = saveAs || (function(view) {
 						var reader = new FileReader();
 						reader.onloadend = function() {
 							var base64Data = reader.result;
-							base64Data = base64Data.replace(/^data:.*;/, 'data:attachment/file;');
+							base64Data = base64Data.replace(/^data:.*?;/, 'data:attachment/file;');
 							target_view.location.href = encodeURI(base64Data);
 							filesaver.readyState = filesaver.DONE;
 							dispatch_all();