In gFTP 2.0.14, in a scenario, where I connect to a FTP server through a
HTTP proxy, only the first connect succeeds. When I try to connect again,
gFTP messes up protocols and proxy settings.

Example testcases:
1) Startup gFTP
2) Enter FTP->Options
3) On the FTP tab enter a working HTTP proxy (like Squid) hostname and port
4) Select Type->HTTP
5) Uncheck "passive file transfers" option (the HTTP proxy takes care of this)
6) Click Save
7) Connect to a FTP server through a bookmark, do some stuff, disconnect
and exit gFTP
8) Launch gFTP, connect to the same FTP server through a bookmark

Outcome:

gFTP tries to connect with HTTP protocol, not FTP (although bookmark
specifies FTP).

When I enter FTP->Options, I can see that FTP proxy type has been reset to
custom, with empty textarea below.

Setting proxy type to "HTTP" isn't persisted - every time I return to
FTP->Options, I always see "Custom" proxy type.

In my case the log for the second, broken connection, shows:

Looking up ftp.club-internet.fr
Trying ftp.club-internet.fr:21
Connected to ftp.club-internet.fr:21
GET
ftp://anonymous@ftp.club-internet.fr/pub/linux/Mandrake-devel/cooker/SRPMS/
HTTP/1.1
User-Agent: gFTP 2.0.14
Host: ftp.club-internet.fr
Authorization: Basic xxxx
220-FTP server ready.220-You are user number 218 of 1500 allowed.220 Only
anonymous FTP is allowed here530 You aren't logged in500 ?500 ?500 ?500 ?