Fix tenant filter logic in Get-CIPPBackup

Updated the tenant filter condition to exclude 'AllTenants' from being treated as a specific tenant filter. This ensures that backups are not incorrectly filtered when 'AllTenants' is specified.

Author: JohnDuprey

Modules/CIPPCore/Public/Get-CIPPBackup.ps1

@@ -31,7 +31,7 @@ function Get-CIPPBackup {
             $Info = $Info | Where-Object { $_.RowKey -match "^$($TenantFilter)_" }
         }
     } else {
-        if ($TenantFilter) {
+        if ($TenantFilter -and $TenantFilter -ne 'AllTenants') {
             $Info = $Info | Where-Object { $_.TenantFilter -eq $TenantFilter }
         }
     }