Port fix from master

libraries/gpu-gl/src/gpu/gl/GLTexture.cpp

@@ -478,6 +478,10 @@ void GLVariableAllocationSupport::updateMemoryPressure() {
 
         // Populate the existing textures into the queue
         for (const auto& texture : strongTextures) {
+            // Race conditions can still leave nulls in the list, so we need to check
+            if (!texture) {
+                continue;
+            }
             addToWorkQueue(texture);
         }
     }