Update templateadmintools.php

add column for templatekey in template list as in justinhunt#51, forgot headspan

classes/templateadmintools.php

@@ -46,7 +46,7 @@ public static function fetch_template_table() {
                 get_string('version'),
                 get_string('description')
         );
-        $table->headspan = array(1, 1, 1);
+        $table->headspan = array(1, 1, 1, 1);
         $table->colclasses = array(
                 'templatenamecol', 'templatekeycol', 'templateversioncol', 'templateinstructionscol'
         );