libs with word instead of filenames fails re-reading

Summary

In case (pisoFoam/LES/pitzDaily) the library loading (in e.g. the functions functionObjectList) uses the new syntax:

libs (sampling)

When forcing re-reading by touching system/controlDict it gives an error since it expects a fileName.

Steps to reproduce

• take above tutorial
• comment out functions section
• start running
• uncomment functions section & save

Relevant logs and/or images

        Re-reading object controlDict from file "ep_1328_fileModification/pitzDaily/system/controlDict"
Overriding OptimisationSwitches according to controlDict
    fileModificationSkew 1;


--> FOAM FATAL IO ERROR: 
Wrong token type - expected string, found on line 58: word 'sampling'

file: ep_1328_fileModification/pitzDaily/system/controlDict.functions.probes.libs at line 58.

    From function Foam::Istream& Foam::operator>>(Foam::Istream&, Foam::fileName&)
    in file primitives/strings/fileName/fileNameIO.C at line 58.

FOAM aborting (FOAM_ABORT set)

Environment information

• OpenFOAM version : v1812