Revised text from Enterprise marketplace pop-up screen

Updated the qml WelcomPage with the revised text:
"Please sign in to get verified plugins and materials for Ultimaker Cura Enterprise"

plugins/Toolbox/resources/qml/pages/WelcomePage.qml

@@ -19,7 +19,7 @@ Column
     Label
     {
         id: welcomeTextLabel
-        text: catalog.i18nc("@description", "Get plugins and materials verified by Ultimaker")
+        text: catalog.i18nc("@description", "Please sign in to get verified plugins and materials for Ultimaker Cura Enterprise")
         width: Math.round(parent.width / 2)
         font: UM.Theme.getFont("default")
         color: UM.Theme.getColor("text")