Filtrer grep failed with pattern "/"

[tguenneguez]

Bug Report

Describe the bug
Filtrer grep failed with pattern "/"

If the pattern contains only one character and that character is "/", then fluent-bit crashes due to the parsing performed in the source code available here.
Voir ici

Furthermore, nowhere in the documentation does it specify that if the pattern begins with a "/" and ends with a "/", these two characters are removed.
This has an impact, for example, if you want to search for the text "/tmp/". In this case, you must search for "//tmp//".

[tguenneguez]

Thanks for commit.
It will be greate to add to the doc that when pattern beggin and end by "/", the both char are removed ?

For exemple if you want to user "/tmp/" pattern to be sure to have the good result you must use "//tmp//"