Fix UnhandledPromiseRejectionWarnings in Node.js

These were introduced in 9bdeaa9 by `await`ing Promises later than
they're created.

src/encoding/armor.js

@@ -313,6 +313,7 @@ function dearmor(input) {
       }));
       data = stream.transformPair(data, async (readable, writable) => {
         const checksumVerified = stream.readToEnd(getCheckSum(stream.passiveClone(readable)));
+        checksumVerified.catch(() => {});
         await stream.pipe(readable, writable, {
           preventClose: true
         });

src/message.js

@@ -586,6 +586,7 @@ Message.prototype.verify = async function(keys, date = new Date(), streaming) {
       });
       onePassSig.signatureData = stream.fromAsync(async () => (await onePassSig.correspondingSig).signatureData);
       onePassSig.hashed = stream.readToEnd(await onePassSig.hash(onePassSig.signatureType, literalDataList[0], undefined, false, streaming));
+      onePassSig.hashed.catch(() => {});
     }));
     msg.packets.stream = stream.transformPair(msg.packets.stream, async (readable, writable) => {
       const reader = stream.getReader(readable);