build: include rc number in version number

configure.ac

@@ -4,11 +4,12 @@ define(_CLIENT_VERSION_MAJOR, 0)
 define(_CLIENT_VERSION_MINOR, 17)
 define(_CLIENT_VERSION_REVISION, 99)
 define(_CLIENT_VERSION_BUILD, 0)
+define(_CLIENT_VERSION_RC, 0)
 define(_CLIENT_VERSION_IS_RELEASE, false)
 define(_COPYRIGHT_YEAR, 2018)
 define(_COPYRIGHT_HOLDERS,[The %s developers])
 define(_COPYRIGHT_HOLDERS_SUBSTITUTION,[[Bitcoin Core]])
-AC_INIT([Bitcoin Core],m4_join([.], _CLIENT_VERSION_MAJOR, _CLIENT_VERSION_MINOR, _CLIENT_VERSION_REVISION, m4_if(_CLIENT_VERSION_BUILD, [0], [], _CLIENT_VERSION_BUILD)),[https://github.com/bitcoin/bitcoin/issues],[bitcoin],[https://bitcoincore.org/])
+AC_INIT([Bitcoin Core],m4_join([.], _CLIENT_VERSION_MAJOR, _CLIENT_VERSION_MINOR, _CLIENT_VERSION_REVISION, m4_if(_CLIENT_VERSION_BUILD, [0], [], _CLIENT_VERSION_BUILD))m4_if(_CLIENT_VERSION_RC, [0], [], [rc]_CLIENT_VERSION_RC),[https://github.com/bitcoin/bitcoin/issues],[bitcoin],[https://bitcoincore.org/])
 AC_CONFIG_SRCDIR([src/validation.cpp])
 AC_CONFIG_HEADERS([src/config/bitcoin-config.h])
 AC_CONFIG_AUX_DIR([build-aux])