npm.bbclass: avoid str/byte conversion problems for PKGV and SUMMARY
In Python3, str.encode() returns byte strings, which later are not
converted back to strings automatically, leading to "TypeError: Can't
convert 'bytes' object to str implicitly" in code which reads PKGV and
SUMMARY and expects to find strings there.
The npm.bbclass must use values for d.setVar() that meet that
expectation, and thus the redundant (and in Python3, harmful)
.encode() gets removed.
Signed-off-by: Patrick Ohly <patrick.ohly@intel.com> Signed-off-by: Ross Burton <ross.burton@intel.com>
