casync: update to latest master

Note that this adds only two commits to the master branch since the
latest changes in 2022.

The current release is still from 2017, which strongly indicates that
the project is actually dead.

Signed-off-by: Enrico Jörns <ejo@pengutronix.de>

Author: ejoerns

recipes-casync/casync/casync_git.bb

@@ -5,7 +5,7 @@ LIC_FILES_CHKSUM = "file://LICENSE.LGPL2.1;md5=4fbd65380cdd255951079008b364516c"
 
 DEPENDS = "xz curl openssl acl zstd"
 
-SRCREV = "0efa7abffe5fffbde8c457d3c8fafbdde0bb6e4f"
+SRCREV = "b4b7e5606f785572b78a43626a27a45fe3df2fbd"
 PV = "2+git${SRCPV}"
 
 SRC_URI = " \