Ampersand in 2 activities title crashes learningmap

[gmanaud]

Hi,

Ampersand sign (&) in title of 2 activities that was used in learning map crashes the activity learning map upon saving the learningmap activity. Image vanishes, can't be re-uploaded. Learningmap activity had to be deleted and set up from start after removing the ampersand in the name of activities.

Problem reported with Moodle 4.1.6 and learningmaps 0.9.5.2
Adding 2 activities with a & in each activity crashes the learningmap activity

Example:
create an activity (page for example) named "&1"
create an other activity named "&2"
create a learningmap activity and add the activity &1 and &2 at the same time

Note that you can add the 2 activities separatly (add &1, save, add &2, save): in this case, the learningmap activity doesn't crash.

Originally posted by @gmanaud in #74 (comment)