When using the useradd-staticids.bbclass under meta/classes,
this error occurs:
"<username> - <username>: Username does not have a static uid defined."
There was a problem with the regular expression for parsing parameters,
it was sometimes returning an empty string.
I have fixed this by skipping empty strings.
Signed-off-by: Fabrice Coulon <fabrice@axis.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>