Fix undefined placeholder in custom address modal when toChain is undefined#373

pedromcunha merged 2 commits intomainrelayprotocol/relay-kit:mainfrom

ted/relay-6302-incorrect-place-holder-text-when-no-destination-currency-isrelayprotocol/relay-kit:ted/relay-6302-incorrect-place-holder-text-when-no-destination-currency-isCopy head branch name to clipboard