CLEANUP: ssl: remove dead code in ssl_sock_load_pem_into_ckch()

Commit 432cd1a ("MEDIUM: ssl: be stricter about chain error")
introduced some dead code, let's remove it.

Should fix issue #1909.
diff --git a/src/ssl_ckch.c b/src/ssl_ckch.c
index 1df6b96..9fcbbaf 100644
--- a/src/ssl_ckch.c
+++ b/src/ssl_ckch.c
@@ -626,8 +626,6 @@
 	while ((ca = PEM_read_bio_X509(in, NULL, NULL, NULL))) {
 		if (chain == NULL)
 			chain = sk_X509_new_null();
-		if (ca == NULL)
-			break;
 		if (!sk_X509_push(chain, ca)) {
 			X509_free(ca);
 			break;