[api] simple test and fixture for _statistics route
[backend] fix minor typo
[backend] make getsslcert also work the first time it is called
[backend] don't commit certs when the signkey is "1"
[backend] switch to RSA@2048 for new signing keys. WARNING: sign must be at least 2.1.5.1 for this to work
[backend] tweak sslcert retrival again to bring to more in line with the signkey handling
[backend] fix spurious next statement in signer
[backend] don't retry signing if the cpio.rsasign is bad
[backend] Fix error message in product converter

ERROR: No such archset HASH(0x28d5080) is not a useful error message.
[backend] do always use package release number as product provides. This basically makes the usage
          of explicit product release numbers not possible anymore, but it seems every product just
          worked around this anyway.
[webui] - patchinfo-editor
- fixed errormessage after adding a wrong issue-format
- added more checks for adding issues to patchinfos
- added more testcases for adding issues