Remove duplicated space before when matched

Running `org.hibernate.orm.test.stateless.UpsertTest`:

Before -> `merge into "UpsertTest$Record" as t using (select cast(? as bigint) id, cast(? as varchar) message) as s on (t.id=s.id) when not matched then insert (id, message) values (s.id, s.message)  when matched then update set message=s.message`
After  -> `merge into "UpsertTest$Record" as t using (select cast(? as bigint) id, cast(? as varchar) message) as s on (t.id=s.id) when not matched then insert (id, message) values (s.id, s.message) when matched then update set message=s.message`

Author: quaff

hibernate-core/src/main/java/org/hibernate/dialect/SqlAstTranslatorWithMerge.java

@@ -242,7 +242,7 @@ protected void renderMergeUpdate(OptionalTableUpdate optionalTableUpdate) {
 	}
 
 	private void renderWhenMatched(List<ColumnValueBinding> optimisticLockBindings) {
-		appendSql( " when matched" );
+		appendSql( "when matched" );
 		for (int i = 0; i < optimisticLockBindings.size(); i++) {
 			final ColumnValueBinding binding = optimisticLockBindings.get( i );
 			appendSql(" and ");

hibernate-core/src/main/java/org/hibernate/dialect/SqlAstTranslatorWithUpsert.java

@@ -193,7 +193,7 @@ protected void renderMergeUpdate(OptionalTableUpdate optionalTableUpdate) {
 		final List<ColumnValueBinding> valueBindings = optionalTableUpdate.getValueBindings();
 		final List<ColumnValueBinding> optimisticLockBindings = optionalTableUpdate.getOptimisticLockBindings();
 
-		appendSql( " when matched then update set " );
+		appendSql( "when matched then update set " );
 		for ( int i = 0; i < valueBindings.size(); i++ ) {
 			final ColumnValueBinding binding = valueBindings.get( i );
 			if ( i > 0 ) {