L1: fix -Wdeprecated-copy warning in L1Vector

reco/L1/L1Algo/L1Vector.h

@@ -42,13 +42,16 @@ public:
   {
   }
 
-  L1Vector(const L1Vector& v) : Tbase(), fName(v.fName)
+  L1Vector(const L1Vector& v) : Tbase() { *this = v; }
+
+  L1Vector& operator=(const L1Vector& v)
   {
-    Tbase::reserve(v.capacity());
+    fName = v.fName;
+    Tbase::reserve(v.capacity());  // make sure that the capacity is transmitted
     Tbase::assign(v.begin(), v.end());
+    return *this;
   }
 
-
   void SetName(const std::string& s) { fName = s; }
 
   void SetName(const std::basic_ostream<char>& s)