Common: EnumFlags turn set with empty string into reset

Signed-off-by: Felix Schlepper <felix.schlepper@cern.ch>

Author: f3sch

Common/Utils/include/CommonUtils/EnumFlags.h

@@ -398,11 +398,14 @@ class EnumFlags
   // Sets flags from a string representation.
   // This can be either from a number representation (binary or digits) or
   // a concatenation of the enums members name e.g., 'Enum1|Enum2|...'
-  void set(const std::string& s, int base = 2)
+  void set(const std::string& s="", int base = 2)
   {
     // on throw restore previous state and rethrow
     const U prev = mBits;
     reset();
+    if (s.empty()) { // no-op
+      return;
+    }
     try {
       setImpl(s, base);
     } catch (const std::exception& e) {