fix #87 by removing empty strings after split operation

this will also avoid problems in case there is ever a double-comma
or a trailing comma in the rc or rccancel properties.

Switching to the .Split() method is safe here because GetAttribute()
always returns a string, not null.

Author: jantari

LSUClient.psm1

@@ -214,9 +214,9 @@ class PackageInstallInfo {
 
     PackageInstallInfo ([System.Xml.XmlElement]$PackageXML) {
         $this.InstallType    = $PackageXML.Install.GetAttribute('type')
-        $this.SuccessCodes   = $PackageXML.Install.GetAttribute('rc') -split ','
-        $this.FailureCodes   = $PackageXML.Install.GetAttribute('rcfailure') -split ','
-        $this.CancelCodes    = $PackageXML.Install.GetAttribute('rccancel') -split ','
+        $this.SuccessCodes   = $PackageXML.Install.GetAttribute('rc').Split(',').Where({ $_ }) # Avoids issue #87
+        $this.FailureCodes   = $PackageXML.Install.GetAttribute('rcfailure').Split(',')
+        $this.CancelCodes    = $PackageXML.Install.GetAttribute('rccancel').Split(',').Where({ $_ }) # Avoids issue #87
         $this.InfFile        = $PackageXML.Install.INFCmd.INFfile
         $this.ExtractCommand = $PackageXML.ExtractCommand
         $this.Command        = $PackageXML.Install.Cmdline.'#text'