configure: clarify zlib error message

Also drop the spurious quotes.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

diff --git a/configure.ac b/configure.ac
index 67062ce..9a3301f 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -244,7 +244,7 @@ dnl zlib is mandatory.
 save_LIBS="$LIBS"
 LIBS=
 eu_ZIPLIB(zlib,ZLIB,z,gzdirect,gzip)
-AS_IF([test "x$with_zlib" = xno], [AC_MSG_ERROR("zlib not found")])
+AS_IF([test "x$with_zlib" = xno], [AC_MSG_ERROR([zlib not found but is required])])
 LIBS="$save_LIBS"
 
 dnl Test for bzlib and xz/lzma, gives BZLIB/LZMALIB .am