configure.ac: fix empty else on RHEL5

Ancient autoconf versions don't like empty
strings in m4 arguments.

diff --git a/configure.ac b/configure.ac
index 56d22c2..4aa3af7 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -1638,7 +1638,7 @@ PKG_CHECK_MODULES([HAL], [hal],
         ])
         CPPFLAGS="$SAVE_CPPFLAGS"
       ],
-      []
+      [ : ]
     )
     LIBS="$SAVE_LIBS"
   ],