Avoid linking to libltdl.so (no longer needed)

diff --git a/ext/mcrypt/config.m4 b/ext/mcrypt/config.m4
index cc68d86..8ae7ee8 100644
--- a/ext/mcrypt/config.m4
+++ b/ext/mcrypt/config.m4
@@ -34,21 +34,13 @@ if test "$PHP_MCRYPT" != "no"; then
 
   PHP_MCRYPT_CHECK_VERSION
 
-  PHP_CHECK_LIBRARY(mcrypt, mcrypt_module_open, 
+  PHP_CHECK_LIBRARY(mcrypt, mcrypt_module_open,
   [
-    PHP_ADD_LIBRARY(ltdl,, MCRYPT_SHARED_LIBADD)
     AC_DEFINE(HAVE_LIBMCRYPT,1,[ ])
   ],[
-    PHP_CHECK_LIBRARY(mcrypt, mcrypt_module_open,
-    [
-      AC_DEFINE(HAVE_LIBMCRYPT,1,[ ])
-    ],[
-      AC_MSG_ERROR([Sorry, I was not able to diagnose which libmcrypt version you have installed.])
-    ],[
-      -L$MCRYPT_DIR/$PHP_LIBDIR
-    ])
+    AC_MSG_ERROR([Sorry, I was not able to diagnose which libmcrypt version you have installed.])
   ],[
-    -L$MCRYPT_DIR/$PHP_LIBDIR -lltdl
+    -L$MCRYPT_DIR/$PHP_LIBDIR
   ])
 
   PHP_ADD_LIBRARY_WITH_PATH(mcrypt, $MCRYPT_DIR/$PHP_LIBDIR, MCRYPT_SHARED_LIBADD)