Updated grade caching so that questions with different question text …

…still use the cached outcome.

That is, something has to change in the actual job being run to force a real regrade.

classes/jobrunner.php

@@ -167,7 +167,7 @@ private function run_combinator($isprecheck) {
         // affect caching. For example the questionid will change each time
         // the question is saved thanks to question versioning - urgh!
         foreach ($this->testcases as $tc) {
-            // unset($tc->id);   May be ok to leave in there????
+            unset($tc->id);
             unset($tc->questionid);
         }
         $numtests = count($this->testcases);
@@ -248,7 +248,7 @@ private function run_tests_singly($isprecheck) {
         // affect caching. For example the questionid will change each time
         // the question is saved thanks to question versioning - urgh!
         foreach ($this->testcases as $tc) {
-            // unset($tc->id);    May be Ok to leave there?
+            unset($tc->id);
             unset($tc->questionid);
         }
         $numtests = count($this->testcases);