Re #8613. Remove code that bails out early if no events in a bank.

We need the bank name to be added to the list even if it's empty as it's
checked for if the BankNames property has been set. There's already a check
that means that no LoadBankFromDiskTask is created for the bank if it's
empty (the original justification for adding this code in commit [3654021]).

I don't think this change has much other effect, but I'll be relying
heavily on the tests to confirm that given the horrific complexity of
the file.

Code/Mantid/Framework/DataHandling/src/LoadEventNexus.cpp

@@ -1425,11 +1425,6 @@ void LoadEventNexus::loadEvents(API::Progress * const prog, const bool monitors)
 
       // get the number of events
       std::size_t num = numEvents(file, hasTotalCounts, oldNeXusFileNames);
-      if (num == 0)
-      {
-        file.closeGroup();
-        continue;
-      }
       bankNames.push_back( entry_name );
       bankNumEvents.push_back(num);
       total_events += num;