Wrong icon size after changing the constants

# Bug Report
The icon in a medium size content element texticon don't resize to a larger value if the constant is changed from default to 60.
plugin.bootstrap_package_contentelements.texticon.icon.medium.height = 60
plugin.bootstrap_package_contentelements.texticon.icon.medium.width = 60

## Prerequisites

* [ ] Can you reproduce the problem on TYPO3 v8.7 LTS
* [x] Can you reproduce the problem on TYPO3 v9.5 LTS
* [x] Did you [perform a cursory search](https://github.com/issues?q=is%3Aissue+user%3Abenjaminkott+repo%3Abenjaminkott%2Fbootstrap_package) to see if your bug or enhancement is already reported?

## Description
If for example the constant plugin.bootstrap_package_contentelements.texticon.icon.medium.height and plugin.bootstrap_package_contentelements.texticon.icon.medium.width is changed to 60 the icon doesnt appear bigger in the frontend even if the img size is 60x60. It stays small (48x48px).

## Steps to Reproduce
1. Change plugin.bootstrap_package_contentelements.texticon.icon.medium.height and plugin.bootstrap_package_contentelements.texticon.icon.medium.width to 60
2. Check the frontend
3. The icon size is 60x60 but the box is still 48x48

**Expected behavior:**

**Actual behavior:**

## Versions
TYPO3 9.5.9 - Bootstrap Package 11.0.1

Reproduce the issue on TYPO3 9.5.9 with Bootstrap Package 11.0.1 using the texticon content element and the two medium icon constants set to 60. Trace the frontend rendering and sizing of the icon; done means the image and its surrounding box both render at 60x60 instead of remaining 48x48.

Written by the indexing model from the issue text.