BUG/MINOR: commit 196729ef used wrong condition resulting in freeing constants

Recent commit 196729ef had inverted condition to free format strings. No
backport is needed, it was never released.
diff --git a/src/cfgparse.c b/src/cfgparse.c
index 5f8cb96..a95f06c 100644
--- a/src/cfgparse.c
+++ b/src/cfgparse.c
@@ -1610,9 +1610,9 @@
 		free(defproxy.expect_str);
 		if (defproxy.expect_regex) regfree(defproxy.expect_regex);
 
-		if (defproxy.logformat_string == default_http_log_format ||
-		    defproxy.logformat_string == default_tcp_log_format ||
-		    defproxy.logformat_string == clf_http_log_format)
+		if (defproxy.logformat_string != default_http_log_format &&
+		    defproxy.logformat_string != default_tcp_log_format &&
+		    defproxy.logformat_string != clf_http_log_format)
 			free(defproxy.logformat_string);
 
 		free(defproxy.uniqueid_format_string);