Prevent PKG_CHECK_MODULES from aborting
Prevent PKG_CHECK_MODULES from aborting

As it turns out, PKG_CHECK_MODULES aborts execution if the
"action-if-not-found" argument is empty.  This breaks our
configure script in platforms that do not have lua5.1.pc.

Add a non-action default value to the macro argument to prevent
this problem.

This change was r53 in Subversion.

rodrigc/kyua,rodrigc/kyua,jmmv/kyua,jmmv/kyua,rodrigc/kyua,jmmv/kyua,rodrigc/kyua,jmmv/kyua