[Freeciv-Dev] (PR#6573) undefined reference to real_sanity_check_city

["Jason Short" <jdorje@xxxxxxxxxxxxxxxxxxxxx>]

When compiling without debugging (--enable-debug=no):

./libcivserver.a(cityhand.o): In function `handle_city_change_specialist':
cityhand.o(.text+0x15d): undefined reference to `real_sanity_check_city'
./libcivserver.a(cityhand.o): In function `handle_city_make_worker':
cityhand.o(.text+0x2a8): undefined reference to `real_sanity_check_city'
./libcivserver.a(cityhand.o): In function `handle_city_make_specialist':
cityhand.o(.text+0x60c): undefined reference to `real_sanity_check_city'
./libcivserver.a(cityhand.o): In function `handle_city_change':
cityhand.o(.text+0xaf7): undefined reference to `real_sanity_check_city'
./libcivserver.a(citytools.o): In function `transfer_city':
citytools.o(.text+0xb36): undefined reference to `real_sanity_check_city'
./libcivserver.a(citytools.o)(.text+0x11b6): more undefined references 
to `real_sanity_check_city' follow