Remove duplicate minus sign in Profiler

[SharkyKZ]

Alternative to #29353 and also fixes errors on PHP 8.

Summary of Changes

Removes double minus sign when storing time and memory in Profiler. This fixes type error on PHP 8 and notices on PHP 7.

Testing Instructions

Enable debug on PHP 8.

Actual result BEFORE applying this Pull Request

round(): Argument #1 ($number) must be of type int|float, string given
C:\wamp\www\joomla-cms-3\plugins\system\debug\debug.php:716

Expected result AFTER applying this Pull Request

No errors.

Documentation Changes Required

Don't think so.

[viocassel]

I have tested this item ✅ successfully on 24a5e42

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[jwaisner]

I have tested this item ✅ successfully on 24a5e42

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_{This comment was created with the J!Tracker Application at issues.joomla.org/tracker/joomla-cms/30582.}

[jwaisner]

RTC

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_{This comment was created with the J!Tracker Application at issues.joomla.org/tracker/joomla-cms/30582.}

[HLeithner]

Waiting to get #29353 merged or rewritten.

[HLeithner]

Thanks