performance - do not check for string == when equals will be called

equals implementation for String begins with  == equality check

h2/src/main/org/h2/engine/Database.java

@@ -2871,7 +2871,7 @@ public class Database implements DataHandler {
      * @return true if they match
      */
     public boolean equalsIdentifiers(String a, String b) {
-        if (a == b || a.equals(b)) {
+        if (a.equals(b)) {
             return true;
         }
         if (!dbSettings.databaseToUpper && a.equalsIgnoreCase(b)) {