Resolves: fdo#55411 python 2 vs 3 str/bytes encoding issues

Change-Id: Ic1aac1609f3a1fcbd0af9a1c9ecc07a735c8785a
diff --git a/scripting/source/pyprov/mailmerge.py b/scripting/source/pyprov/mailmerge.py
index 18b476c..f70f034 100755
--- a/scripting/source/pyprov/mailmerge.py
+++ b/scripting/source/pyprov/mailmerge.py
@@ -239,11 +239,14 @@ class PyMailSMTPService(unohelper.Base, XSmtpService):
			encode_base64(msgattachment)
			fname = attachment.ReadableName
			try:
				fname.encode('ascii')
				msgattachment.add_header('Content-Disposition', 'attachment', \
					filename=fname)
			except:
				fname = ('utf-8','',fname.encode('utf-8'))
			msgattachment.add_header('Content-Disposition', 'attachment', \
				filename=fname)
				msgattachment.add_header('Content-Disposition', 'attachment', \
					filename=('utf-8','',fname))
			if dbg:
				print(("PyMailSMTPService attachmentheader: ", str(msgattachment)), file=dbgout)

			msg.attach(msgattachment)

		uniquer = {}