RMG Options: make "Computer only teams" buttons work as expected

Button "0" should be always enabled and if "Computer only players" set to "0" we should also computer only team count to "0" if it's not random.

client/CPreGame.cpp

@@ -1698,7 +1698,7 @@ CRandomMapTab::CRandomMapTab()
 	compOnlyPlayersCntGroup->addCallback([&](int btnId)
 	{
 		mapGenOptions.setCompOnlyPlayerCount(btnId);
-		deactivateButtonsFrom(compOnlyTeamsCntGroup, btnId);
+		deactivateButtonsFrom(compOnlyTeamsCntGroup, (btnId == 0 ? 1 : btnId));
 		validateCompOnlyPlayersCnt(btnId);
 		if(!SEL->isGuest())
 			updateMapInfo();
@@ -1709,7 +1709,7 @@ CRandomMapTab::CRandomMapTab()
 	compOnlyTeamsCntGroup->pos.y += 351;
 	compOnlyTeamsCntGroup->pos.x += BTNS_GROUP_LEFT_MARGIN;
 	addButtonsWithRandToGroup(compOnlyTeamsCntGroup, numberDefs, 0, 6, NUMBERS_WIDTH, 234, 241);
-	deactivateButtonsFrom(compOnlyTeamsCntGroup, 0);
+	deactivateButtonsFrom(compOnlyTeamsCntGroup, 1);
 	compOnlyTeamsCntGroup->addCallback([&](int btnId)
 	{
 		mapGenOptions.setCompOnlyTeamCount(btnId);
@@ -1826,8 +1826,9 @@ void CRandomMapTab::validateCompOnlyPlayersCnt(int compOnlyPlayersCnt)
 
 	if(mapGenOptions.getCompOnlyTeamCount() >= compOnlyPlayersCnt)
 	{
-		mapGenOptions.setCompOnlyTeamCount(compOnlyPlayersCnt - 1);
-		compOnlyTeamsCntGroup->setSelected(mapGenOptions.getCompOnlyTeamCount());
+		int compOnlyTeamCount = compOnlyPlayersCnt == 0 ? 0 : compOnlyPlayersCnt - 1;
+		mapGenOptions.setCompOnlyTeamCount(compOnlyTeamCount);
+		compOnlyTeamsCntGroup->setSelected(compOnlyTeamCount);
 	}
 }