extra plugins aren't loaded anymore

[SuperStormer]

• [ x] Did you use the latest version of GEF from dev branch?
• [ x] Is your bug specific to GEF (not GDB)? - Try to reproduce it running gdb -nx
• [ x] Did you search through the documentation first?
• [x ] Did you check issues (including the closed ones) - and the PR?

Step 1: Describe your environment

• Operating System / Distribution: Debian bookworm

• Architecture: amd64

• GEF version (including the Python library version) run version in GEF.

GEF: (Standalone)
Blob Hash(/home/larry/.gdbinit-gef.py): 72dee13ebd87dad52d24dc5d04469c142e64dbd1
SHA256(/home/larry/.gdbinit-gef.py): 835d765cd6b5dfaf4b2a80d0e146b696cb29ba89ad2a43509e02ef8f636a1fd1
GDB: 10.1.90.20210103-git
GDB-Python: 3.10

Step 2: Describe your problem

Steps to reproduce

1. cd /opt && git clone https://github.com/hugsy/gef-extras
2. start gdb and run gef config gef.extra_plugins_dir /opt/gef-extras/scripts
3. observe that extra commands are loaded
4. run gef save
5. quit and then rerun gdb
6. observe that extra commands aren't being loaded

Observed Results

extra commands aren't being loaded

Expected results

extra commands are loaded when you start up GDB, ie.

[+] 38 extra commands added from '/opt/gef-extras/scripts'

displays

Traces

bf959a3

I think the call to load_extra_plugins() was accidentally removed here? The only time it gets called now is in on_write in the config command for extra_plugins_dir (which is why gef config ... still loads the extra plugins).