configure.in: bumped version number to 0.8.6

The jump in version numbers has been suggested by Raul Fuentes, see
http://dev.eclipse.org/mhonarc/lists/tinydtls-dev/msg00005.html
diff --git a/configure.in b/configure.in
index 7ee9f94..ebd5b58 100644
--- a/configure.in
+++ b/configure.in
@@ -15,7 +15,7 @@
 #    Hauke Mehrtens - memory optimization, ECC integration
 
 AC_PREREQ([2.65])
-AC_INIT([tinydtls], [0.8.2])
+AC_INIT([tinydtls], [0.8.6])
 AC_CONFIG_SRCDIR([dtls.c])
 dnl AC_CONFIG_HEADERS([config.h])