Set order of LiquibaseDBLockProviderFactory to 1

- makes it the default provider when no provider is explicitly configured
- avoid NPE at server startup when other providers are present and none is set as default

model/jpa/src/main/java/org/keycloak/connections/jpa/updater/liquibase/lock/LiquibaseDBLockProviderFactory.java

@@ -30,6 +30,7 @@ import org.keycloak.models.dblock.DBLockProviderFactory;
 public class LiquibaseDBLockProviderFactory implements DBLockProviderFactory {
 
     private static final Logger logger = Logger.getLogger(LiquibaseDBLockProviderFactory.class);
+    public static final int PROVIDER_PRIORITY = 1;
 
     private long lockWaitTimeoutMillis;
 
@@ -68,4 +69,9 @@ public class LiquibaseDBLockProviderFactory implements DBLockProviderFactory {
     public String getId() {
         return "jpa";
     }
+
+    @Override
+    public int order() {
+        return PROVIDER_PRIORITY;
+    }
 }