Update README.md with not about vendor folders.

go fmt

Author: chappjc

README.md

@@ -160,6 +160,10 @@ There is a [very long to-do list](https://drive.google.com/open?id=1Z057i7tGfnAT
 
 * Find dcrspy executable in `$GOPATH/bin`, and copy elsewhere (recommended).
 
+If you receive build errors, it may be due to "vendor" directories left by
+glide builds of dependencies such as dcrwallet.  You may safely delete vendor
+folders.
+
 ## Updating
 
 Run the same command used to build:

main.go

@@ -97,7 +97,7 @@ func main() {
 
 	// watchaddress
 	var recvTxChan, spendTxChan chan *watchedAddrTx
-	if len(cfg.WatchAddresses) > 0  && !cfg.NoMonitor {
+	if len(cfg.WatchAddresses) > 0 && !cfg.NoMonitor {
 		recvTxChan = make(chan *watchedAddrTx, 80)
 		spendTxChan = make(chan *watchedAddrTx, 80)
 	}