newtmgr serial; don't start command with empty line. This gets target to print console prompt, confusing newtmgr when it's reading response back.
newtmgr serial; don't start command with empty line.
This gets target to print console prompt, confusing newtmgr
when it's reading response back.

apache/incubator-mynewt-newt,apache/incubator-mynewt-newt