Update the the PathMatchingResourcePatternResolver used in the
MessageSourceAutoConfiguration condition to deal with the fact
that `classpath*:` patterns do not work with URLClassLoaders when
the pattern doesn't include a folder.
The ExtendedPathMatchingResourcePatternResolver works by searching
all classpath URLs when the `findAllClassPathResources` method is
called with an empty location.
Fixes gh-1378
eb721b1e9f