Fix date time user do not work on chrome With Timezone

[ThierryHund]

No description provided.

[ThierryHund]

Test case, Chrome on windows french, Create a Project, create a task.
$_SESSION["dol_tz_string"]="Europe, Madrid (heure d'été)".
This not not a correct timezone for PHP DateTimeZone($time zone).
We try to get a better fix to get the real timezone from dst.js and convert it to PHP timezone without succes, at least this fix will avoid bug when create a task

[eldy]

I tried this fix instead that looks better:
bf96a78

[FHenry]

With your last commit bf96a78, I think it will be ok. It should wrk now. I can't try on windows OS. I've done this pullrequest in coordination with Tierry, during a Git/GitHub/Eclipse/Dolibarr trainning.
Thierry you should receive this by email, could try with a Pull on 3.6 branch to create a task ?