Webui: Support setting an alternative port than 8080 to host the webui on

git-svn-id: svn://svn.icculus.org/fs2open/trunk/fs2_open@10045 387891d4-d844-0410-90c0-e4c51a9137d3
Webui: Clarify the use of branching if statements, to be consistent with existing code

git-svn-id: svn://svn.icculus.org/fs2open/trunk/fs2_open@10046 387891d4-d844-0410-90c0-e4c51a9137d3