Fix encodedWord regular expression(RFC 2047) to match quoted email addresses properly.

E.g of quoted email address: "From: \"=?ISO-8859-1?Q?=22Joh=F1_D=F6e=22?=\" <jdoe@example.net>"

Change-Id: I640fb127d640585099289558c6080cd1b698c331
Signed-off-by: Valerio Valerio <valerio.valerio@jollamobile.com>
Reviewed-by: Matthew Vogt <matthew.vogt@qinetic.com.au>