Merge #5125

5125: Fix server loading map twice on startup r=def- a=Zwelf

Fixes creating two teehistorian files. And probably increases performance :). Fixes #5121 

## Checklist

- [x] Tested the change ingame
- [ ] Provided screenshots if it is a visual change
- [ ] Tested in combination with possibly related configuration options
- [ ] Written a unit test if it works standalone, system.c especially
- [ ] Considered possible null pointers and out of bounds array indexing
- [x] 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: Zwelf <zwelf@strct.cc>

src/engine/server/server.cpp

@@ -2383,6 +2383,8 @@ void CServer::ChangeMap(const char *pMap)
 
 int CServer::LoadMap(const char *pMapName)
 {
+	m_MapReload = false;
+
 	char aBuf[IO_MAX_PATH_LENGTH];
 	str_format(aBuf, sizeof(aBuf), "maps/%s.map", pMapName);
 	GameServer()->OnMapChange(aBuf, sizeof(aBuf));
@@ -2602,8 +2604,6 @@ int CServer::Run()
 			// load new map TODO: don't poll this
 			if(m_MapReload)
 			{
-				m_MapReload = false;
-
 				// load map
 				if(LoadMap(Config()->m_SvMap))
 				{