Mms: Fix unicode stripping

twice set of input filter on the textedit area overwrote
the strip unicode feature. lengthFilter is already
set on line 2120...so remove the other inputfilter duplicate

Change-Id: Ifce79b2bb616fd96610aac1500ddc1f8141b84de

Conflicts:
	src/com/android/mms/ui/ComposeMessageActivity.java