Patch error in getdns tests to fix FTBFS with gcc-14. (Closes: #1074989)

Fix incorrectly-written assertion breaking builds with gcc-14. An assertion in test code was written incorrectly in a way that would always succeed. This patch was independently developed to fix the Debian build but the bug is also fixed as part of a larger patch fixing compiler warnings upstream which is present in v1.7.0~rc.1 onwards.

Importing the latest upstream release will obviate the need for this patch.