Merge #5833

5833: Improve message on failed load r=heinrich5991 a=def-


![Screenshot 2022-09-13 at 20 31 20](https://user-images.githubusercontent.com/2335377/189982324-91639abd-6f5b-4248-85f9-5e03443e6182.png)

## Checklist

- [x] Tested the change ingame
- [x] Provided screenshots if it is a visual change
- [ ] Tested in combination with possibly related configuration options
- [ ] Written a unit test (especially base/) or added coverage to integration test
- [ ] Considered possible null pointers and out of bounds array indexing
- [ ] Changed no physics that affect existing maps
- [ ] Tested the change with [ASan+UBSan or valgrind's memcheck](https://github.com/ddnet/ddnet/#using-addresssanitizer--undefinedbehavioursanitizer-or-valgrinds-memcheck) (optional)


Co-authored-by: Dennis Felsing <dennis@felsin9.de>

src/game/server/scoreworker.cpp

@@ -1530,7 +1530,11 @@ bool CScoreWorker::LoadTeam(IDbConnection *pSqlServer, const ISqlData *pGameData
 	}
 	if(!Found)
 	{
-		str_copy(pResult->m_aMessage, "You don't belong to this team", sizeof(pResult->m_aMessage));
+		str_copy(pResult->m_aMessage, "This save exists, but you are not part of it. "
+					      "Make sure you use the same name as you had when saving. "
+					      "If you saved with an already used code, you get a new random save code, "
+					      "check ddnet-saves.txt in config_directory.",
+			sizeof(pResult->m_aMessage));
 		return false;
 	}