Add 1.9.0-rc1 version definition

Author: cedric-anne

treeview.xml

@@ -25,6 +25,11 @@
       <author>Teclib'</author>
    </authors>
    <versions>
+      <version>
+          <num>1.9.0-rc1</num>
+          <compatibility>~9.5.0</compatibility>
+          <download_url>https://github.com/pluginsGLPI/treeview/releases/download/1.9.0-rc1/glpi-treeview-1.9.0-rc1.tar.bz2</download_url>
+      </version>
       <version>
           <num>1.8.1</num>
           <compatibility>~9.4.0</compatibility>