BUG: Initialize ctest_coverage command ivar

This initializes the LabelsMentioned ivar in cmCTestCoverageCommand.

Source/CTest/cmCTestCoverageCommand.cxx

@@ -19,6 +19,13 @@
 #include "cmCTest.h"
 #include "cmCTestCoverageHandler.h"
 
+//----------------------------------------------------------------------------
+cmCTestCoverageCommand::cmCTestCoverageCommand()
+{
+  this->LabelsMentioned = false;
+}
+
+//----------------------------------------------------------------------------
 cmCTestGenericHandler* cmCTestCoverageCommand::InitializeHandler()
 {
   this->CTest->SetCTestConfigurationFromCMakeVariable(this->Makefile,

Source/CTest/cmCTestCoverageCommand.h

@@ -28,7 +28,7 @@ class cmCTestCoverageCommand : public cmCTestHandlerCommand
 {
 public:
 
-  cmCTestCoverageCommand() {}
+  cmCTestCoverageCommand();
 
   /**
    * This is a virtual constructor for the command.