bump version

master should have a higher version than stable branch

Author: raveit65

configure.ac

@@ -1,7 +1,7 @@
 AC_PREREQ([2.60])
 
 m4_define([msd_api_version_major],[1])
-m4_define([msd_api_version_minor],[20])
+m4_define([msd_api_version_minor],[21])
 m4_define([msd_api_version_micro],[0])
 m4_define([msd_api_version],
 	[msd_api_version_major.msd_api_version_minor.msd_api_version_micro])