Make sure HexChat won't run in portable mode if the user doesn't select it

win32/installer/hexchat-x64.skel.iss

@@ -260,6 +260,7 @@ begin
 			begin
 				UnInstallOldVersion();
 			end;
+			DeleteFile(ExpandConstant('{app}\portable-mode'));
 		end;
 	end;
 end;

win32/installer/hexchat-x86.skel.iss

@@ -261,6 +261,7 @@ begin
 			begin
 				UnInstallOldVersion();
 			end;
+			DeleteFile(ExpandConstant('{app}\portable-mode'));
 		end;
 	end;
 end;