Misc (#951): fixed compilation warning on gcc/Linux

git-svn-id: https://svn.pjsip.org/repos/pjproject/trunk@3006 74dad513-b988-da41-8d7b-12977e46ad98
diff --git a/pjlib/src/pj/ssl_sock_ossl.c b/pjlib/src/pj/ssl_sock_ossl.c
index 6ac1278..ae7549a 100644
--- a/pjlib/src/pj/ssl_sock_ossl.c
+++ b/pjlib/src/pj/ssl_sock_ossl.c
@@ -248,7 +248,7 @@
 
     errstr.ptr = buf;
     errstr.slen = pj_ansi_snprintf(buf, bufsize, 
-				   "Unknown OpenSSL error %ul",
+				   "Unknown OpenSSL error %lu",
 				   ssl_err);
 
     return errstr;