Restore +dev suffix

Signed-off-by: Paul Fertser <fercerpav@gmail.com>

configure.ac

@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0-or-later
 
 AC_PREREQ([2.69])
-AC_INIT([openocd], [0.12.0-rc3],
+AC_INIT([openocd], [0.12.0-rc3+dev],
   [OpenOCD Mailing List <openocd-devel@lists.sourceforge.net>])
 AC_CONFIG_SRCDIR([src/openocd.c])
 AC_CONFIG_AUX_DIR([build-aux])