Maelstrom: Update deathmatch game mode when toggled in the lobby.

https://github.com/libsdl-org/Maelstrom/commit/46912848d6cb058ba77f797056fc1289be2c94a9

From 46912848d6cb058ba77f797056fc1289be2c94a9 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Fri, 25 Nov 2011 13:23:57 -0500
Subject: [PATCH] Update deathmatch game mode when toggled in the lobby.

---
 game/gameinfo.cpp | 1 -
 game/lobby.cpp    | 8 +++++++-
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/game/gameinfo.cpp b/game/gameinfo.cpp
index b0bc786c..54c539d1 100644
--- a/game/gameinfo.cpp
+++ b/game/gameinfo.cpp
@@ -42,7 +42,6 @@ GameInfo::Reset()
 	wave = 0;
 	lives = 0;
 	turbo = 0;
-	deathMatch = 0;
 	gameMode = 0;
 	deathMatch = 0;
 	numNodes = 0;
diff --git a/game/lobby.cpp b/game/lobby.cpp
index 4dbfb305..797995f3 100644
--- a/game/lobby.cpp
+++ b/game/lobby.cpp
@@ -347,7 +347,13 @@ LobbyDialogDelegate::GlobalGameChanged(void*)
 void
 LobbyDialogDelegate::SetDeathmatch(void*, int value)
 {
-	m_game.deathMatch = (Uint8)value;
+	if (value) {
+		m_game.gameMode |= GAME_MODE_DEATHMATCH;
+		m_game.deathMatch = (Uint8)value;
+	} else {
+		m_game.gameMode &= ~GAME_MODE_DEATHMATCH;
+		m_game.deathMatch = 0;
+	}
 }
 
 void