improve error message if libvips not found

jcupitt · jcupitt · commit 38202971c24a · 2017-02-08T16:54:59.000Z
see libvips/php-vips#31
diff --git a/config.m4 b/config.m4
@@ -16,7 +16,7 @@ fi
 
 if test x"$PHP_VIPS" != x"no"; then
   if ! pkg-config vips --atleast-version $VIPS_MIN_VERSION; then
-    AC_MSG_ERROR([you need at least vips $VIPS_MIN_VERSION for this module])
+    AC_MSG_ERROR([you need at least libvips $VIPS_MIN_VERSION for this module])
     PHP_VIPS=no
   fi
 fi
