Minor: fix highlighting in "query clause" step of code tour

Author: shati-patel

.tours/codeql-tutorial.tour

@@ -34,7 +34,7 @@
         },
         "end": {
           "line": 8,
-          "character": 8
+          "character": 9
         }
       }
     },
@@ -70,4 +70,4 @@
       ]
     }
   ]
-}
+}