Remove extra symbols in `de` that are not defined in DIN 2137-01:2018-12.
I found a couple of codes with symbols, that are not defined in DIN 2137-01:2018-12.
I suggest to leave them in NoSymbol
state. It eases future adding of new symbols when the norm develops further and avoids trouble.
@mshugo: thank you for your good work!
Edited by Jens Getreu