More on ticket #535: updated files using and related to math.h

git-svn-id: https://svn.pjsip.org/repos/pjproject/trunk@1961 74dad513-b988-da41-8d7b-12977e46ad98
diff --git a/pjlib/include/pjlib.h b/pjlib/include/pjlib.h
index ec027fc..523efdb 100644
--- a/pjlib/include/pjlib.h
+++ b/pjlib/include/pjlib.h
@@ -42,6 +42,7 @@
 #include <pj/list.h>
 #include <pj/lock.h>
 #include <pj/log.h>
+#include <pj/math.h>
 #include <pj/os.h>
 #include <pj/pool.h>
 #include <pj/pool_buf.h>