Fix megalinter

Author: Marcellocosti

PWGHF/D2H/Tasks/taskB0Reduced.cxx

@@ -40,6 +40,7 @@
 #include <array>
 #include <cstdint>
 #include <numeric>
+#include <string>
 
 using namespace o2;
 using namespace o2::aod;

PWGHF/TableProducer/candidateSelectorDstarToD0Pi.cxx

@@ -41,7 +41,6 @@
 #include <Rtypes.h>
 
 #include <cstdint>
-#include <string>
 #include <vector>
 
 using namespace o2;