MINOR: ssl: remove OpenSSL 1.0.2 mention into certificate loading error

Remove the mention to OpenSSL 1.0.2 in the certificate chain loading
error, which is not relevant.

Could be backported in 2.7.
diff --git a/src/ssl_sock.c b/src/ssl_sock.c
index 740fc0a..cb544d4 100644
--- a/src/ssl_sock.c
+++ b/src/ssl_sock.c
@@ -3389,7 +3389,7 @@
 #ifdef SSL_CTX_set1_chain
 	if (!SSL_CTX_set1_chain(ctx, *find_chain)) {
 		ret = ERR_get_error();
-		memprintf(err, "%sunable to load chain certificate into SSL Context '%s': %s. Make sure you are linking against Openssl >= 1.0.2.\n",
+		memprintf(err, "%sunable to load chain certificate into SSL Context '%s': %s.\n",
 			  err && *err ? *err : "", path,  ERR_reason_error_string(ret));
 		errcode |= ERR_ALERT | ERR_FATAL;
 		goto end;