phase1, phase2: exclude temporary source files from sourceupload step

phase1, phase2: exclude temporary source files from sourceupload step

When the dl/ directory is shared with several workers, there can be
temporary "*.hash" and "*.dl" files being created by other workers.
These files should be excluded from the sourceupload step, otherwise it
can cause a failure when rsync tries to read them.

See for example:

  https://buildbot.openwrt.org/master/packages/#/builders/14/builds/18/steps/39/logs/stdio

Signed-off-by: Baptiste Jonglez <git@bitsofnetworks.org>