ftp/php74-ftp: Fix Undefined symbol "SSL_library_init"

The ftp module always compiles against the base openssl,
causes the error on FreeBSD 11.3. All other ports based
on OpenSSL import the needed openssl from ports, if its
not in base. Therefore we adjust the behaviour of the
ftp module to match for example the imap module.

PR: 241591
Submitted by: Pascal Christen <pascal.christen@hostpoint.ch>