The index for table `block_grade_me_quiz_ngrade` is not properly defined

[djarran]

Description: The index for the block_grade_me_quiz_ngrade is defined in the <KEYS> tag:

moodle-block_grade_me/db/install.xml

Lines 42 to 45 in a5d2547

	<KEYS>
	<KEY NAME="primary" TYPE="primary" FIELDS="id" NEXT="userid-questionattemptstepid" />
	<INDEX NAME="userid-questionattemptstepid" UNIQUE="false" FIELDS="userid, questionattemptstepid"/>
	</KEYS>