This also rebuilds recipes which use the EXTERNALSRC_GIT_SRCREV variable, when the variable changes.
Signed-off-by: Lucien Mueller <lucien.mueller@netmodule.com>
version string generated with 'git describe' contains -dirty marker if
not all changes have been commited before.
Signed-off-by: Patrick Zysset <patrick.zysset@netmodule.com>