Refined the partnerid and accounttype check in the /create route according to the /doc/Send-requirements.md
Both are not mandatory but if given, they should be strings.
The typeof check is for direct string initialisation with "".
instanceof is used for string initialisation with new String() / the primitiv wrapper class.
I'm not 100% sure which way is used there so I've put both ways in.
Refined the partnerid and accounttype check in the /create route according to the /doc/Send-requirements.md Both are not mandatory but if given, they should be strings.
The typeof check is for direct string initialisation with "". instanceof is used for string initialisation with new String() / the primitiv wrapper class. I'm not 100% sure which way is used there so I've put both ways in.
Also, please control it, I've not tested it #296