Fix some crashes

Sources/Client/Client.cpp

@@ -491,6 +491,11 @@ namespace spades {
 
 			if (!world->GetLocalPlayer() || world->GetLocalPlayer()->GetTeamId() >= 2) {
 				// join
+				if (team == 255) {
+					// weaponId doesn't matter for spectators, but
+					// NetClient doesn't like invalid weapon ID
+					weap = WeaponType::RIFLE_WEAPON;
+				}
 				net->SendJoin(team, weap, playerName, lastKills);
 			} else {
 				Player *p = world->GetLocalPlayer();

Sources/Client/World.h

@@ -117,7 +117,7 @@ namespace spades {
 			void SetMode(IGameMode *);
 
 			Team &GetTeam(int t) {
-				if (t >= 2) // spectator
+				if (t >= 2 || t < 0) // spectator
 					return teams[2];
 				return teams[t];
 			}