[#5273] Update nightly build version tags to conform dpkg rules

tools/build-system/launch-build-machine-2.sh

@@ -22,6 +22,7 @@ DO_LOGGING=1
 DO_UPLOAD=1
 SNAPSHOT_TAG=`date +%Y%m%d`
 TAG_NAME_PREFIX=
+VERSION_NUMBER="0.9.13"
 
 LAUNCHPAD_PACKAGES=( "sflphone-client-gnome" "sflphone-common" )
 
@@ -150,7 +151,7 @@ if [ ${IS_RELEASE} ]; then
 	COMMIT_HASH_BEGIN="${PREVIOUS_RELEASE_COMMIT_HASH}"
 	LAUNCHPAD_CONF_PREFIX="sflphone"
 else
-	SOFTWARE_VERSION="snapshot${SNAPSHOT_TAG}"
+	SOFTWARE_VERSION="${VERSION_NUMBER}-rc${SNAPSHOT_TAG}"
 	COMMIT_HASH_BEGIN="${CURRENT_RELEASE_COMMIT_HASH}"
 	LAUNCHPAD_CONF_PREFIX="sflphone-nightly"
 fi