Fix ubuntu-impish-amd64 build errors.

Oh no! See !2339 (comment 742117548)

/<<BUILDDIR>>/remmina-1.4.21+ppa202111232119.rcfbb56577.d7db90dc4a~ubuntu21.10.1/src/remmina.c: In function ‘main’:
/<<BUILDDIR>>/remmina-1.4.21+ppa202111232119.rcfbb56577.d7db90dc4a~ubuntu21.10.1/src/remmina.c:333:17: error: format not a string literal and no format arguments [-Werror=format-security]
  333 |                 g_message(g_strdup_printf("%s\n%s\n",
      |                 ^~~~~~~~~
cc1: some warnings being treated as errors
make[3]: *** [src/CMakeFiles/remmina.dir/build.make:168: src/CMakeFiles/remmina.dir/remmina.c.o] Error 1
make[3]: *** Waiting for unfinished jobs....

I didn't have any warnings or errors while building localy with both old and new versions.

I rewrote it anyways now, hope it fixes your build problem.