--prefix does not work with absolute path

[moogly81]

if I run :
s3-parallel-put --bucket=mybucket --prefix=myfiles data.txt
then s3://mybucket/myfiles/data.txt is present (as expected)

but if I run this (with an absolute path)
s3-parallel-put --bucket=mybucket --prefix=myfiles /data.txt
then I expect
s3://mybucket/myfiles/data.txt
but I get
s3://mybucket/data.txt

as a workaround I have to use relative path if I want to use a prefix

[cbarbour]

I can confirm that the merged commit fixes this issue.