improved output of condition check on error

source/RobotAPI/libraries/core/checks/ConditionCheckMagnitudeChecks.cpp

 #include "ConditionCheckMagnitudeChecks.h"
 
+#include <ArmarXCore/core/util/StringHelpers.h>
+
 namespace armarx
 {
 
@@ -22,8 +24,7 @@ namespace armarx
 
         if (dataFields.size() != 1)
         {
-            printf("Size of dataFields: %d\n", (int)dataFields.size());
-            throw InvalidConditionException("Wrong number of datafields for condition equals ");
+            throw InvalidConditionException("Wrong number of datafields for condition magnitude larger: expected 1 actual: " + ValueToString(dataFields.size()));
         }
 
         const Variant& value = dataFields.begin()->second;