Fix error 500 when opening tracked links on email when logged

[Enc3phale]

Please be sure you are submitting this against the staging branch.

Q	A
Bug fix?	Y
New feature?	N
Automated tests included?	N
Related user documentation PR URL	N
Related developer documentation PR URL	N
Issues addressed (#s or URLs)	#6400
BC breaks?	N
Deprecations?	N

Description:

Fix error 500 when opening tracked links on email when logged in to Mautic.
Since the trackedContact can be null it was missing a condition.

Steps to reproduce the bug:

1. Create an email for a campaign and add a link with the builder
2. Create a campaign to send the mail
3. Send mail to a contact
4. Open the sent email and click on any link
5. Mautic will raise a 500 error

Steps to test this PR:

1. Apply the PR
2. It's now good

[escopecz]

This code change cannot hurt 👍

[guizero]

Thanks for that @Enc3phale!

[vitordesousa]

Thanks @Enc3phale!

[nartcan]

Thank you.

[Pixman]

Hello,
I suggest you can change the line 173 of the file app/bundles/LeadBundle/Helper/ContactRequestHelper.php
On my platform this modfication correct a 500 error code bug if a connected admin click on email link.

- if ($foundContact->getId() !== $this->trackedContact->getId()) {
+ if ($this->trackedContact && $foundContact->getId() !== $this->trackedContact->getId()) {

[mabdelfattah]

@Pixman I tried your patch but it did not work, I'm getting the following error instead:

mautic.CRITICAL: Uncaught PHP Exception Symfony\Component\Debug\Exception\FatalThrowableError: "Call to a member function isAnonymous() on null" at /app/bundles/LeadBundle/Helper/ContactRequestHelper.php line 242 {"exception":"[object] (Symfony\\Component\\Debug\\Exception\\FatalThrowableError(code: 0): Call to a member function isAnonymous() on null at /app/bundles/LeadBundle/Helper/ContactRequestHelper.php:242)"}