Always inject FinishedJobs instance into ProgressServiceImpl #1887

The "finishedJobs" variable isn´t injected, thus is always null, when used
from a progress dialog. Since the @optional field in combination with @Inject
only refers to already created instances of FinishedJobs. But, this does
not happen in this flow.

Fixes #1887

bundles/org.eclipse.e4.ui.progress/src/org/eclipse/e4/ui/progress/internal/ProgressServiceImpl.java

@@ -58,7 +58,6 @@ public class ProgressServiceImpl implements IProgressService {
 	ProgressManager progressManager;
 
 	@Inject
-	@Optional
 	FinishedJobs finishedJobs;
 
 	@Inject