cmake: restore -fvisibility=hidden flag
cmake: restore -fvisibility=hidden flag

This removed when the manual flag manipulation bit was removed. This
restores the previous behavior and adds -fvisibility-inlines-hidden

Signed-off-by: GitHub <1505422b2465e9a84f6fdfaa161078890c593f06@github.com>

alanxz/rabbitmq-c,alanxz/rabbitmq-c,alanxz/rabbitmq-c