MDL-55739 core_course: Check if gradepass is set and not empty

Default value of gradepass is 0.00000 and empty check
passes. But on oracle gradepass value is 0, so just
check if the field is set and that should be enough

course/modlib.php

@@ -701,7 +701,7 @@ function get_moduleinfo_data($cm, $course) {
         foreach ($items as $item) {
             if (!empty($item->outcomeid)) {
                 $data->{'outcome_' . $item->outcomeid} = 1;
-            } else if (!empty($item->gradepass)) {
+            } else if (isset($item->gradepass)) {
                 $decimalpoints = $item->get_decimals();
                 $data->gradepass = format_float($item->gradepass, $decimalpoints);
             }