Description of problem:

When FTP client appends ";type=a" in the requested URL, squid chops the last character of the filename.

FTP clients == (GET ftp://ftp.example.com/test.txt;type=a ) ==> squid == (GET "test.tx") ==> FTP server.

Version-Release number of selected component (if applicable):
squid-4.11-4

How reproducible:
all the time

Steps to Reproduce:

0. Create a user on FTP server.
   Username: user
   Password: password
1. Start squid
2. Connect to squid with `telnet`.
3. Try to get "test.txt" from ftp server via squid.
4. You will see squid tries to get "test.tx" instead of "test.txt".

Actual results:
$ telnet ip
Trying ip...
Connected to ip.
Escape character is '^]'.
GET ftp://user@ip/test.txt;type=a HTTP/1.1
Authorization: Basic

HTTP/1.1 404 Not Found
Server: squid/5.1
Mime-Version: 1.0
Date: Sun, 19 Sep 2021 03:51:31 GMT
Content-Type: text/html;charset=utf-8
Content-Length: 3972
X-Squid-Error: ERR_FTP_NOT_FOUND 0
Vary: Accept-Language
Content-Language: en
X-Cache: MISS from user.example.com
Via: 1.1 user.example.com (squid/5.1)
Connection: keep-alive

... snip ...

<p>The following URL could not be retrieved: <a href="ftp://user@ip/test.tx">ftp://user@ip/test.tx</a></p>

... snip ...

Expected results:

$ telnet ip port
Trying ip...
Connected to ip.
Escape character is '^]'.
GET ftp://user@ip/test.txt;type=a HTTP/1.1
Authorization: Basic 

HTTP/1.1 200 Gatewaying
Server: squid/5.1
Mime-Version: 1.0
Date: Sun, 19 Sep 2021 03:57:27 GMT
Content-Type: text/plain
Last-Modified: Sat, 18 Sep 2021 19:15:46 GMT
X-Cache: MISS from host.example.com
Transfer-Encoding: chunked
Via: 1.1 host.example.com (squid/5.1)
Connection: keep-alive

Additional info:

If you remove ";type=a" from the URL, squid can retrieve the file successfully.