Fix JS code for checking of correct non-response

Fix the JS code written at the end of a routine so
that it checks to see if it was a non-response before
evaluating if the non-response was the correct answer.

This fixes a problem where normal correct responses
are not written to the data file

psychopy/app/builder/components/keyboard/__init__.py

@@ -490,10 +490,12 @@ def writeRoutineEndCodeJS(self, buff):
 
         if self.params['storeCorrect'].val:  # check for correct NON-repsonse
             code = ("// was no response the correct answer?!\n"
-                    "if (psychoJS.str(%(correctAns)s).toLowerCase() == 'none') {\n"
-                    "   %(name)s.corr = 1  // correct non-response\n"
-                    "} else {\n"
-                    "   %(name)s.corr = 0  // failed to respond (incorrectly)\n"
+                    "if (%(name)s.keys == undefined) {\n"
+                    "  if (psychoJS.str(%(correctAns)s).toLowerCase() == 'none') {\n"
+                    "     %(name)s.corr = 1  // correct non-response\n"
+                    "  } else {\n"
+                    "     %(name)s.corr = 0  // failed to respond (incorrectly)\n"
+                    "  }\n"
                     "}\n"
                     % self.params)