Due to Tycho bug 368596 we didn't package the correct JGit source bundle
anymore. Instead of sources it contained the binary bundle. As a
workaround fall back to use packaging type eclipse-update-site which
doesn't seem to have this problem.
Bug: 368596
Bug: 379402
Change-Id: I3192dbd00b51e6ee6596d2301050b2a6f7028e3b
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>