Fix: regex in numeric Values in meta-data

[gast04]

I do not know all the details, but the regex seems wrong, as numeric values are prefixed with \ [backslash and space] (as stated in another discussion, https://stackoverflow.com/questions/2154945/how-to-force-a-meta-data-value-to-type-string , and in the file itself).

This won't match with the current regex, meaning all values are non numeric.
For example if I add a log:

MetadataValue NOT numeric: '\ 34173474129'

which is a numeric value.

In my case this leads to an issue, changing the regex and replace the unnecessary trim with a substring(2). fixes it in my case.

Not sure about any side effect, need to do a bit more testing. Just wanted to drop it here, in case anyone else has issues with numeric metadata values.

[iBotPeaches]

Okay, I fear we will need some unit-tests for this. We keep changing this and I now assume I don't even know the right answer.

[gast04]

totally agree, I will try adding unit-tests for that tomorrow, and fixing the ones that are currently failing.