CLOS-3827: Add a new Imunify GPG package signature to the CloudLinux list

Some Imunify packages are now signed with a new key, and its signature was not recognized by leapp - which caused these packages to be skipped during upgrades.

Author: prilr

repos/system_upgrade/common/files/distro/cloudlinux/gpg-signatures.json

@@ -5,7 +5,8 @@
         "429785e181b961a5",
         "51d6647ec21ad6ea",
         "d36cb86cb86b3716",
-        "2ae81e8aced7258b"
+        "2ae81e8aced7258b",
+        "bc9a243190e02617"
     ],
     "packager": "CloudLinux Packaging Team"
 }