Bugfix custom port check

[JoshuaMart]

• Fix for Ports Flag is not working with scheme #704 & Could not cast port to integer #712
• Add New test case

I tested locally and my change seems to solve the problem, I tested via the following commands :

 echo "example.com" | ./httpx -ports 443
 echo "example.com" | ./httpx -ports 442-443
 echo "example.com" | ./httpx -ports https:443
 echo "example.com" | ./httpx -ports http:80,https:443

[ehsandeep]

@JoshuaMart thanks for the PR, this is now fixed in #714 with some additional improvements.