streams: Remove special cases for ancient MSVC

Quite sure that we haven't supported MSVC 6.0 for ages (MSC_VER 1300 is
>= MSVC++ 7.0) but with the C++11 switch we can be sure.

src/streams.h

@@ -174,12 +174,10 @@ public:
         Init(nTypeIn, nVersionIn);
     }
 
-#if !defined(_MSC_VER) || _MSC_VER >= 1300
     CDataStream(const char* pbegin, const char* pend, int nTypeIn, int nVersionIn) : vch(pbegin, pend)
     {
         Init(nTypeIn, nVersionIn);
     }
-#endif
 
     CDataStream(const vector_type& vchIn, int nTypeIn, int nVersionIn) : vch(vchIn.begin(), vchIn.end())
     {
@@ -261,7 +259,6 @@ public:
             vch.insert(it, first, last);
     }
 
-#if !defined(_MSC_VER) || _MSC_VER >= 1300
     void insert(iterator it, const char* first, const char* last)
     {
         assert(last - first >= 0);
@@ -274,7 +271,6 @@ public:
         else
             vch.insert(it, first, last);
     }
-#endif
 
     iterator erase(iterator it)
     {