Fix crash on null PlayerExtraOptionsPanel (#551)

* Fix crash on null PlayerExtraOptionsPanel

* Follow codestyle

Author: SadPencil

DXMainClient/DXGUI/Multiplayer/GameLobby/GameLobbyBase.cs

@@ -468,20 +468,23 @@ protected void ApplyPlayerExtraOptions(string sender, string message)
         {
             var playerExtraOptions = PlayerExtraOptions.FromMessage(message);
 
-            if (playerExtraOptions.IsForceRandomSides != PlayerExtraOptionsPanel.IsForcedRandomSides())
-                AddPlayerExtraOptionForcedNotice(playerExtraOptions.IsForceRandomSides, "side selection".L10N("Client:Main:SideAsANoun"));
+            if (PlayerExtraOptionsPanel != null)
+            {
+                if (playerExtraOptions.IsForceRandomSides != PlayerExtraOptionsPanel.IsForcedRandomSides())
+                    AddPlayerExtraOptionForcedNotice(playerExtraOptions.IsForceRandomSides, "side selection".L10N("Client:Main:SideAsANoun"));
 
-            if (playerExtraOptions.IsForceRandomColors != PlayerExtraOptionsPanel.IsForcedRandomColors())
-                AddPlayerExtraOptionForcedNotice(playerExtraOptions.IsForceRandomColors, "color selection".L10N("Client:Main:ColorAsANoun"));
+                if (playerExtraOptions.IsForceRandomColors != PlayerExtraOptionsPanel.IsForcedRandomColors())
+                    AddPlayerExtraOptionForcedNotice(playerExtraOptions.IsForceRandomColors, "color selection".L10N("Client:Main:ColorAsANoun"));
 
-            if (playerExtraOptions.IsForceRandomStarts != PlayerExtraOptionsPanel.IsForcedRandomStarts())
-                AddPlayerExtraOptionForcedNotice(playerExtraOptions.IsForceRandomStarts, "start selection".L10N("Client:Main:StartPositionAsANoun"));
+                if (playerExtraOptions.IsForceRandomStarts != PlayerExtraOptionsPanel.IsForcedRandomStarts())
+                    AddPlayerExtraOptionForcedNotice(playerExtraOptions.IsForceRandomStarts, "start selection".L10N("Client:Main:StartPositionAsANoun"));
 
-            if (playerExtraOptions.IsForceRandomTeams != PlayerExtraOptionsPanel.IsForcedRandomTeams())
-                AddPlayerExtraOptionForcedNotice(playerExtraOptions.IsForceRandomTeams, "team selection".L10N("Client:Main:TeamAsANoun"));
+                if (playerExtraOptions.IsForceRandomTeams != PlayerExtraOptionsPanel.IsForcedRandomTeams())
+                    AddPlayerExtraOptionForcedNotice(playerExtraOptions.IsForceRandomTeams, "team selection".L10N("Client:Main:TeamAsANoun"));
 
-            if (playerExtraOptions.IsUseTeamStartMappings != PlayerExtraOptionsPanel.IsUseTeamStartMappings())
-                AddPlayerExtraOptionForcedNotice(!playerExtraOptions.IsUseTeamStartMappings, "auto ally".L10N("Client:Main:AutoAllyAsANoun"));
+                if (playerExtraOptions.IsUseTeamStartMappings != PlayerExtraOptionsPanel.IsUseTeamStartMappings())
+                    AddPlayerExtraOptionForcedNotice(!playerExtraOptions.IsUseTeamStartMappings, "auto ally".L10N("Client:Main:AutoAllyAsANoun"));
+            }
 
             SetPlayerExtraOptions(playerExtraOptions);
             UpdateMapPreviewBoxEnabledStatus();