luci-base: prevent parsing the form input after cbi emergency save

Signed-off-by: Jo-Philipp Wich <jow@openwrt.org>

modules/luci-base/luasrc/cbi.lua

@@ -324,6 +324,7 @@ function Map.__init__(self, config, ...)
 				luci.http.redirect(url)
 			end
 		end
+		self.save = false
 	end
 
 	if not ok then