Disable chatroom creation if cell_chknochat

[Emistry]

Pull Request Prelude

• I have followed proper Hercules code styling.
• I have read and understood the contribution guidelines before making this PR.
• I am aware that this PR may be closed if the above-mentioned criteria are not fulfilled.

Changes Proposed

• doesn't allow chatroom creation/switch if the coordinated cell are set with cell_nochat.
• chatroom will be auto deleted.

Details

-	script	sample	-1,{

	OnInit:
		.@map$ = "prontera";
		
		.@max_x = getmapinfo(MAPINFO_SIZE_X, .@map$);
		.@max_y = getmapinfo(MAPINFO_SIZE_Y, .@map$);
		setcell(.@map$, 0, 0, .@max_x, .@max_y, cell_nochat, true);
		
		.@range = 10;
		.@center_x = 155;
		.@center_y = 181;
		setcell(.@map$, (.@center_x - .@range), (.@center_y - .@range), (.@center_x + .@range), (.@center_y + .@range), cell_nochat, false);
		end;
}

player 1 - create a normal chatroom at normal cells that dont have cell_nochat.
player 2 - move to cell_nochat area, and join the chatroom
player 1 - leave the chatroom
** at this point, chatroom shall be auto deleted since the new owner are located in the cell_nochat area.

Issues addressed:
#1569

[HerculesWSAPI]

This change is 

[bWolfie]

Nice one! Much better solution than what I was using where player on nochat cell just can't join the chat.