Fix use of == in configure.ac
A user points out that we're now using == in configure.ac, which isn't portable.
We'll need to backport a fix everywhere that we backported our legacy/trac#34078 (moved) fix.
A user points out that we're now using == in configure.ac, which isn't portable.
We'll need to backport a fix everywhere that we backported our legacy/trac#34078 (moved) fix.