Fixed bug in AddRegion failing to completely add regions

An invalid SQL query selecting the region ID from the newly inserted
region prevented the AddRegion method from completely adding a region,
even though it was inserted into the database correctly, leading to a
`false` result even though the region add was successful.

This fixes /region define, and HouseRegions.

TShockAPI/DB/RegionManager.cs

@@ -140,7 +140,7 @@ public bool AddRegion(int tx, int ty, int width, int height, string regionname,
 					"INSERT INTO Regions (X1, Y1, width, height, RegionName, WorldID, UserIds, Protected, Groups, Owner, Z) VALUES (@0, @1, @2, @3, @4, @5, @6, @7, @8, @9, @10);",
 					tx, ty, width, height, regionname, worldid, "", 1, "", owner, z);
 				int id;
-				using (QueryResult res = database.QueryReader("SELECT Id FROM Regions WHERE RegionName = @0 AND WorldID = @1", regionname, worldid))
+				using (QueryResult res = database.QueryReader("SELECT Id FROM Regions WHERE RegionName = '@0' AND WorldID = '@1'", regionname, worldid))
 				{
 					id = res.Get<int>("Id");
 				}