fix EXT-6766 The number of characters allowed in the Chat Edit Window in Vewer...

fix EXT-6766 The number of characters allowed in the Chat Edit Window in Vewer 2 is 1/2 that in Vewer 1
reviewed Mike Antipov
https://codereview.productengine.com/secondlife/r/305/

--HG--
branch : product-engine

indra/newview/skins/default/xui/en/panel_nearby_chat_bar.xml

@@ -17,7 +17,7 @@
      layout="topleft"
      left_delta="3"
      left="0"
-     max_length="512"
+     max_length="1024"
      name="chat_box"
      text_pad_left="5"
      text_pad_right="25"