release: update NEWS

NEWS

+======================================================
+network-manager-applet-1.4.6
+Overview of changes since network-manager-applet-1.4.4
+======================================================
+
+This is a new stable release of network-manager-applet.  Notable changes include:
+
+* Avoid unnecessarily requesting permission to access firewalld
+* Warn when editing a connection that has properties we don't recognize
+    Useful when running with newer NetworkManager daemon
+* API documentation for libnma is now built
+* Added build options to enable LTO and section garbage collection
+* Bug fixes
+* Updated Brazilian, Catalan, Danish, Italian, Polish and Serbian
+    translations
+
 ======================================================
 network-manager-applet-1.4.4
 Overview of changes since network-manager-applet-1.4.2