Bug 1632002. Re-enable WebRender on Gen7.5 in Nightly.

Scrolling on Youtube (Bug 1576637) has improved enough
that we can turn gen7 back on in Nightly

Differential Revision: https://phabricator.services.mozilla.com/D71859

widget/GfxDriverInfo.cpp

@@ -474,7 +474,7 @@ const GfxDeviceFamily* GfxDriverInfo::GetDeviceFamily(DeviceFamily id) {
       APPEND_DEVICE(0x163d);
       APPEND_DEVICE(0x163e);
 
-#ifdef MOZ_WIDGET_GTK
+#if defined(MOZ_WIDGET_GTK) || defined(NIGHTLY_BUILD)
       // Gen7.5 not allowed until bug 1576637 is resolved.
       APPEND_DEVICE(0x0412);
       APPEND_DEVICE(0x0416);