Bug #303146 --> Shortcut for Paste as Quotation (control-shift-V) missing.

restore missing keyboard command.

mail/components/compose/content/editorOverlay.xul

@@ -63,6 +63,7 @@
 
     <key id="increaseindentkb"  key="&formatindent.keybinding;"  observes="cmd_indent"  modifiers="accel"/>
     <key id="decreaseindentkb"  key="&formatoutdent.keybinding;"  observes="cmd_outdent"  modifiers="accel"/>
+    <key id="pastequotationkb"  key="&editpastequotation.keybinding;"   observes="cmd_pasteQuote"  modifiers="accel, shift"/>
 
     <key id="removestyleskb"       key="&formatremovestyles.keybinding;"   observes="cmd_removeStyles"  modifiers="accel, shift"/>
     <key id="removestyleskb2"       key=" "   observes="cmd_removeStyles"  modifiers="accel"/>