Fix couple of issues found by coverity scan

src/libstat/backends/redis_backend.c

 		}
 	}
 
-	if (target == NULL) {
+	if (target == NULL || task == NULL) {
 		return tlen;
 	}
 

src/libutil/http.c

 									priv->local_key, priv->msg->peer_key);
 						}
 					}
+					else {
+						rspamd_pubkey_unref (pk);
+					}
 				}
 			}
 

src/libutil/regexp.c

 		res->raw_re = pcre2_compile (real_pattern, PCRE2_ZERO_TERMINATED,
 					regexp_flags & ~PCRE_FLAG(UTF),
 					&err_code, &err_off, pcre2_ctx);
-		if (r == NULL) {
+		if (res->raw_re == NULL) {
 			err_str = g_alloca (1024);
 			memset (err_str, 0, 1024);
 			pcre2_get_error_message (err_code, err_str, 1024);

src/rspamadm/configdump.c

 		nobj = ucl_object_fromstring_common ("/*", 0, 0);
 	}
 	else {
+		rspamd_fstring_free (comment);
 		return;
 	}