Qualify make_tuple with boost:: namespace.

db.cpp has a number of uses of make_tuple and has 'using namespace
std' and 'using namespace boost'. Without qualifying make_tuple,
std::make_tuple is preferred, which is incorrect. This patch qualifies
make_tuple.

Signed-off-by: Jeff Garzik <jgarzik@exmulti.com>

src/db.cpp

@@ -610,7 +610,7 @@ bool CWalletDB::WriteAccount(const string& strAccount, const CAccount& account)
 
 bool CWalletDB::WriteAccountingEntry(const CAccountingEntry& acentry)
 {
-    return Write(make_tuple(string("acentry"), acentry.strAccount, ++nAccountingEntryNumber), acentry);
+    return Write(boost::make_tuple(string("acentry"), acentry.strAccount, ++nAccountingEntryNumber), acentry);
 }
 
 int64 CWalletDB::GetAccountCreditDebit(const string& strAccount)
@@ -638,7 +638,7 @@ void CWalletDB::ListAccountCreditDebit(const string& strAccount, list<CAccountin
         // Read next record
         CDataStream ssKey;
         if (fFlags == DB_SET_RANGE)
-            ssKey << make_tuple(string("acentry"), (fAllAccounts? string("") : strAccount), uint64(0));
+            ssKey << boost::make_tuple(string("acentry"), (fAllAccounts? string("") : strAccount), uint64(0));
         CDataStream ssValue;
         int ret = ReadAtCursor(pcursor, ssKey, ssValue, fFlags);
         fFlags = DB_NEXT;