Error if .firewall was null for file in BlockHost()

cleanW10.ps1

@@ -26,6 +26,9 @@ function BlockHost {
         [object]$params
     )
     if ( $params.ContainsKey('file') ) {
+        if ( -not $params.ContainsKey('firewall') -or $params.firewall -eq "" ) {
+            $params.firewall = $false
+        }
         Get-Content $params.file | where { $_ -notmatch "^#.*$|^$" } | Foreach{ BlockHost -params @{host=$_;firewall=$params.firewall} }
     }
     elseif ( $params.ContainsKey('host') -and $params.host -ne "" ) {