Unify s_client/s_server srtp profiles option handling

Add missing guards around STRP-related fields
Remove two unneeded global variables: my 2'cents to #4679
Merge definition and instantiation of srpsrvparm global.

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Ben Kaduk <kaduk@mit.edu>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4908)
diff --git a/apps/s_client.c b/apps/s_client.c
index 4b7df0c..ce7366f 100644
--- a/apps/s_client.c
+++ b/apps/s_client.c
@@ -367,8 +367,6 @@
 
 #endif
 
-static char *srtp_profiles = NULL;
-
 #ifndef OPENSSL_NO_NEXTPROTONEG
 /* This the context that we pass to next_proto_cb */
 typedef struct tlsextnextprotoctx_st {
@@ -657,8 +655,10 @@
     OPT_R_OPTIONS,
     {"sess_out", OPT_SESS_OUT, '>', "File to write SSL session to"},
     {"sess_in", OPT_SESS_IN, '<', "File to read SSL session from"},
+#ifndef OPENSSL_NO_SRTP
     {"use_srtp", OPT_USE_SRTP, 's',
      "Offer SRTP key management with a colon-separated profile list"},
+#endif
     {"keymatexport", OPT_KEYMATEXPORT, 's',
      "Export keying material using label"},
     {"keymatexportlen", OPT_KEYMATEXPORTLEN, 'p',
@@ -934,6 +934,7 @@
     int srp_lateuser = 0;
     SRP_ARG srp_arg = { NULL, NULL, 0, 0, 0, 1024 };
 #endif
+    char *srtp_profiles = NULL;
 #ifndef OPENSSL_NO_CT
     char *ctlog_file = NULL;
     int ct_validation = 0;