merge

src/main/java/com/alibaba/druid/wall/spi/MySqlWallVisitor.java

@@ -300,6 +300,7 @@ public class MySqlWallVisitor extends MySqlASTVisitorAdapter implements WallVisi
             varName = varName.substring(2);
         }
 
+        varName = varName.toLowerCase();
         return config.getDenyVariants().contains(varName);
     }
 
@@ -515,4 +516,4 @@ public class MySqlWallVisitor extends MySqlASTVisitorAdapter implements WallVisi
     public boolean visit(SQLCreateTriggerStatement x) {
         return false;
     }
-}
+}