Opening a graph does not center the nodes properly

Steps to reproduce:

1. Create and open an empty project and install com.unity.behavior
2. Create a behavior graph (Assets > Create > Behavior > Behavior Graph)
3. Open the graph and notice that it is displaying text "Press Space or Right Click to add your first action."
4. Add some nodes and move all of them somewhere far away (see attached video)
5. Close the graph and reopen it

Actual results: The nodes are not centered

Expected results: The nodes are centered

Reproducible with versions: 1.0.8

Tested on (OS): MacOS

Notes:

• I suspect this is because the text "Press Space or Right Click to add your first action." is being taken as a node when centering