lib: remove extra @LIBS@ from pkg-config file
lib: remove extra @LIBS@ from pkg-config file

At the moment it is empty, so probably it does not exist. Remove it to
avoid adding spurious content to the pkg-config file in case that
variable will get a value in the future.

mlichvar/augeas,hercules-team/augeas,hercules-team/augeas,ptoscano/augeas,mlichvar/augeas,mlichvar/augeas,ptoscano/augeas,ptoscano/augeas