build: bump the hinted-at drbd-utils version to 9.3

Author: lge

README.drbd-utils

@@ -4,9 +4,10 @@
   (tarball at http://links.linbit.com/drbd-download)
 
   That started out as "drbd-utils version 8.9.0",
+  has a different release cycle,
   and provides compatible drbdadm, drbdsetup and drbdmeta tools
   for DRBD module versions 8.3, 8.4 and 9.
 
   Again: to manage DRBD 9 kernel modules and above,
-  you want drbd-utils >= 8.9.11 from above url.
+  you want drbd-utils >= 9.3 from above url.
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