Fix the Apple Darwin port.

diff --git a/configure b/configure
index 3c5862f..25987bf 100644
--- a/configure
+++ b/configure
@@ -1215,7 +1215,7 @@
 	MAKEFILE_BSDLIB=$srcdir/lib/Makefile.bsd-lib
 	LIB_EXT=.so
 	case "$host_os" in
-	darwin.*)
+	darwin*)
 		MAKEFILE_BSDLIB=$srcdir/lib/Makefile.darwin-lib
 		LIB_EXT=.dylib
 	;;