Remove unused variables

src/miner.cpp

@@ -1599,7 +1599,6 @@ void static RamhashMiner()
             LogPrintf("Running HushRamhashMiner with %u transactions in block (%u bytes)\n",pblock->vtx.size(),::GetSerializeSize(*pblock,SER_NETWORK,PROTOCOL_VERSION));
 
             // Search
-            arith_uint256 bnMaxPoSdiff; int mids[256],nonzpkeys,i,j,externalflag;
             uint32_t savebits;
             int64_t nStart = GetTime();
             pblock->nBits  = GetNextWorkRequired(pindexPrev, pblock, Params().GetConsensus());