Fix leak for openssl > 3.0 and fix all openssl deprecations

[michaelortmann]

Found by: michaelortmann
Patch by: michaelortmann
Fixes:

One-line summary:
Fix leak for openssl > 3.0 and fix all openssl deprecations

Additional description (if needed):
Fix leak for openssl > 3.0

The leak is happening in ssl_getuid() which is called only in dcc_telnet_id() for telnet over ssl when ssl-cert-auth is set to 2. This PR fixes the leak for eggdrop using openssl >= 3.0.

Fix openssl 1.1 deprecation SSLeay_version() -> OpenSSL_version()
Fix openssl 1.1 deprecation ERR_free_strings()
Fix openssl 3.0 deprecation SSL_get_peer_certificate()
Fix openssl 1.1 deprecation X509_get_notBefore() and X509_get_notAfter() and make ssl_printtime() parameter const

Test cases demonstrating functionality (if applicable):
Fixes the following errors when openssl 3.4.1 is compiled with no-deprecated:
1.

chanprog.c: In function ‘tell_verbose_status’:
chanprog.c:300:11: error: implicit declaration of function ‘SSLeay_version’; did you mean ‘SSL_version’? [-Wimplicit-function-declaration]
  300 |           SSLeay_version(SSLEAY_VERSION), MISC_HEADERVERSION);
      |           ^~~~~~~~~~~~~~
      |           SSL_version
chanprog.c:300:26: error: ‘SSLEAY_VERSION’ undeclared (first use in this function); did you mean ‘SSL3_VERSION’?
  300 |           SSLeay_version(SSLEAY_VERSION), MISC_HEADERVERSION);
      |                          ^~~~~~~~~~~~~~
      |                          SSL3_VERSION

tls.c: In function ‘ssl_init’:
tls.c:132:5: error: implicit declaration of function ‘ERR_free_strings’; did you mean ‘ERR_load_strings’? [-Wimplicit-function-declaration]
  132 |     ERR_free_strings();
      |     ^~~~~~~~~~~~~~~~
      |     ERR_load_strings

tls.c: In function ‘ssl_getcert’:
tls.c:346:10: error: implicit declaration of function ‘SSL_get_peer_certificate’; did you mean ‘SSL_get1_peer_certificate’? [-Wimplicit-function-declaration]
  346 |   return SSL_get_peer_certificate(td->socklist[i].ssl);
      |          ^~~~~~~~~~~~~~~~~~~~~~~~
      |          SSL_get1_peer_certificate
tls.c:346:10: error: returning ‘int’ from a function with return type ‘X509 *’ {aka ‘struct x509_st *’} makes pointer from integer without a cast [-Wint-conversion]
  346 |   return SSL_get_peer_certificate(td->socklist[i].ssl);
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

tls.c: In function ‘ssl_showcert’:
tls.c:694:24: error: implicit declaration of function ‘X509_get_notBefore’; did you mean ‘X509_getm_notBefore’? [-Wimplicit-function-declaration]
  694 |   from = ssl_printtime(X509_get_notBefore(cert));
      |                        ^~~~~~~~~~~~~~~~~~
      |                        X509_getm_notBefore
tls.c:694:24: error: passing argument 1 of ‘ssl_printtime’ makes pointer from integer without a cast [-Wint-conversion]
  694 |   from = ssl_printtime(X509_get_notBefore(cert));
      |                        ^~~~~~~~~~~~~~~~~~~~~~~~
      |                        |
      |                        int