message: Fix GCC 7.4.0 warning
  Warning: enumeral and non-enumeral type in conditional expression.
diff: @@ -2266,7 +2266,7 @@ void MaybeResendWalletTxs()
  CWallet::Balance CWallet::GetBalance(const int min_depth, bool avoid_reuse) const
  {
  Balance ret;
  - isminefilter reuse_filter = avoid_reuse ? 0 : ISMINE_USED;
  + isminefilter reuse_filter = avoid_reuse ? ISMINE_NO : ISMINE_USED;
  {
  auto locked_chain = chain().lock();
  LOCK(cs_wallet);
  