fix(mikrotik): fix check_file_exists mikrotik output handling #808

Job	Run time
linters	39s
Std Test on Python 3.9 (ubuntu-24.04)	46s
Std Test on Python 3.12 (ubuntu-24.04)	44s
Std Test on Python 3.11 (ubuntu-24.04)	45s
Std Test on Python 3.9 (windows-2022)	1m 20s
Std Test on Python 3.11 (windows-2022)	1m 30s
Std Test on Python 3.10 (windows-2022)	1m 27s
Std Test on Python 3.13 (ubuntu-24.04)	40s
Std Test on Python 3.10 (macos-13)	1m 26s
Std Test on Python 3.12 (macos-14)	58s
Std Test on Python 3.11 (macos-13)	1m 33s
Std Test on Python 3.10 (ubuntu-24.04)	44s
Parsers Test on Python 3.11 (ubuntu-24.04)	51s
Std Test on Python 3.13.0-beta.2 (macos-14)	1m 21s
Std Test on Python 3.13 (windows-2022)	1m 21s
Std Test on Python 3.12 (windows-2022)	3m 14s
Std Test on Python 3.9 (macos-13)	1m 21s
	20m 40s

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