Avoid warning message when executable is a binary (Fixes BUGZ-4119)

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This merge request is automatically cherrypicked from !1611 (merged) from source branch https://source.coderefinery.org/nordugrid/arc/-/tree/fix_bug4119_nullbyte orginally made by @maikenp .
The original MR went to branch: https://source.coderefinery.org/nordugrid/arc/-/tree/master

The following commits were omitted due to cherrypick failures or deliberately skipped since they are merge commits from master or next branch:
[ 43b6710b ]
Inspect the merge request and only merge if you are sure everything that should be included is included.
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