Don't let multiple JunitTests operate in parallel on ScDDELinksObj.ods

...seen a failure of JunitTest_sc_unoapi_3 with

> checking: [sc.ScDDELinkObj::com::sun::star::util::XRefreshable] is iface: [com.sun.star.util.XRefreshable] testcode: [ifc.util._XRefreshable]
> LOG> Execute: refresh()
> LOG> starting required method: addRefreshListener()
> LOG> Execute: addRefreshListener()
> Method addRefreshListener() finished with state OK
> LOG> addRefreshListener(): COMPLETED.OK
> warn:unotools.misc:30768:84:unotools/source/misc/mediadescriptor.cxx:690: caught Exception "" while opening <file:///data/lo/core/sc/qa/unoapi/testdocuments/ScDDELinksObj.ods>
> warn:filter.config:30768:84:filter/source/config/cache/typedetection.cxx:455: caught Exception "Could not open stream for <file:///data/lo/core/sc/qa/unoapi/testdocuments/ScDDELinksObj.ods>" while querying type of <file:///data/lo/core/sc/qa/unoapi/testdocuments/ScDDELinksObj.ods>
> Method refresh() finished with state FAILED

and it appears that all of sc.ScDDELinkObj, sc.ScDDELinksObj, and
sc.ScIndexEnumeration_DDELinksEnumeration try to open that file (necessarily for
writing?), and the first two are in JunitTest_sc_unoapi_3 (so are executed
sequentially), but the last one is in JunitTest_sc_unoapi_4 (so may be executed
in parallel with the others), so that may be the reason for such sporadic
failure.  Easiest workaround appears to be to move the third test into the same
JunitTest as the other two...

Change-Id: Iefb94cf657bdc9c1eac92dd49ee6257eb5e80905

sc/qa/unoapi/sc_3.sce

@@ -26,3 +26,4 @@
 -o sc.ScConsolidationDescriptor
 -o sc.ScDDELinkObj
 -o sc.ScDDELinksObj
+-o sc.ScIndexEnumeration_DDELinksEnumeration

sc/qa/unoapi/sc_4.sce

@@ -33,4 +33,3 @@
 -o sc.ScHeaderFooterTextObj
 -o sc.ScIndexEnumeration_CellAnnotationsEnumeration
 -o sc.ScIndexEnumeration_CellAreaLinksEnumeration
--o sc.ScIndexEnumeration_DDELinksEnumeration