Advance configure.ac to version 4.3.1

configure.ac

@@ -14,7 +14,7 @@ dnl Please do not use '-' in the version number, as package managers will fail,
 dnl however, the use of '~' should be fine as apt (others?) will treat
 dnl it as an earlier version than the actual release.  TNX KA6MAL
 dnl PACKAGE_NAME + " " + PACKAGE_VERSION must not exceed 20 chars!
-AC_INIT([Hamlib],[4.3],[hamlib-developer@lists.sourceforge.net],[hamlib],[http://www.hamlib.org])
+AC_INIT([Hamlib],[4.3.1],[hamlib-developer@lists.sourceforge.net],[hamlib],[http://www.hamlib.org])
 
 AC_CONFIG_SRCDIR([include/hamlib/rig.h])
 AC_CONFIG_MACRO_DIR([macros])