fix warning: variable ‘nMinDepth’ set but not used [-Wunused-but-set-variable]

Signed-off-by: Giel van Schijndel <me@mortis.eu>

src/rpc.cpp

@@ -765,9 +765,9 @@ Value movecmd(const Array& params, bool fHelp)
     string strFrom = AccountFromValue(params[0]);
     string strTo = AccountFromValue(params[1]);
     int64 nAmount = AmountFromValue(params[2]);
-    int nMinDepth = 1;
     if (params.size() > 3)
-        nMinDepth = params[3].get_int();
+        // unused parameter, used to be nMinDepth, keep type-checking it though
+        (void)params[3].get_int();
     string strComment;
     if (params.size() > 4)
         strComment = params[4].get_str();