Fix GCC pedantic warnings.

Framework/API/inc/MantidAPI/HistoryItem.h

@@ -44,7 +44,6 @@ class MANTID_API_DLL HistoryItem {
 public:
   HistoryItem(AlgorithmHistory_const_sptr algHist);
   virtual ~HistoryItem() = default;
-  ;
   bool isUnrolled() const { return m_unrolled; }
   void unrolled(bool unrolled) { m_unrolled = unrolled; }
   AlgorithmHistory_const_sptr getAlgorithmHistory() const {

Framework/DataHandling/inc/MantidDataHandling/GroupDetectors2.h

@@ -142,7 +142,6 @@ private:
     /// this class can't be constructed it is just a holder for some static
     /// things
     RangeHelper() = default;
-    ;
     /// give an enum from poco a better name here
     enum {
       IGNORE_SPACES =

Framework/Nexus/inc/MantidNexus/NexusClasses.h

@@ -114,7 +114,6 @@ public:
   NXObject(const NXhandle fileID, const NXClass *parent,
            const std::string &name);
   virtual ~NXObject() = default;
-  ;
   /// Return the NX class name for a class (HDF group) or "SDS" for a data set;
   virtual std::string NX_class() const = 0;
   // True if complies with our understanding of the www.nexusformat.org

Framework/TestHelpers/inc/MantidTestHelpers/WorkspaceCreationHelper.h

@@ -52,7 +52,6 @@ class MockAlgorithm : public Mantid::API::Algorithm {
 public:
   MockAlgorithm(size_t nSteps = 100);
   ~MockAlgorithm() override = default;
-  ;
 
   /// Algorithm's name for identification
   const std::string name() const override { return "MockAlgorithm"; };