odd UI glitch in gtk3 version

[Jack <ostroffjh sbcglobal net>]

As I'm now testing with the gtk3 version (webkit) I found a strange  
difference from the gtk2 version.  In the old version, when I compose a  
new message (actually new or reply) the Recipients section starts out  
with only one line, and adds additional lines as I add recipients.   
With the gtk3 version,  it starts with the Recipients area being three  
lines tall.  Then, if I actually have three recipients (or more) the  
area remains three lines tall, with a scroll bar.  The old version  
expanded that section as needed, at least to show four lines plus a bit.

I'll be glad to provide screen shots if it would be useful.

Jack