related to tdf#73691 - don't conflict with menu hotkeys

Although German (de) was remapped to use Alt-C instead, it still
assigned the en-US alt-X assignment as well, and accelerators
take precedence over menu ~ indicated keys.  So a blank assignment
needs to be made in the alt-X accelerator for any language that conflicts.

Added vietnamese as well - it conflicts with both alt-x and alt-c, so not
assigning any accelerator to it for now.  A vietnamese can request and suggest
an appropriate accelerator combination.

Change-Id: Id972f5125ccab5eaca72b6a114099a5b441b055d
Reviewed-on: https://gerrit.libreoffice.org/20365Reviewed-by: Samuel Mehrbrodt <Samuel.Mehrbrodt@cib.de>
Tested-by: Samuel Mehrbrodt <Samuel.Mehrbrodt@cib.de>
(cherry picked from commit f0282aed)
Reviewed-on: https://gerrit.libreoffice.org/20389

officecfg/registry/data/org/openoffice/Office/Accelerators.xcu

@@ -212,6 +212,12 @@
         <prop oor:name="Command">
           <value xml:lang="x-no-translate">I10N SHORTCUTS - NO TRANSLATE</value>
           <value xml:lang="en-US" install:module="unxwnt">.uno:UnicodeNotationToggle</value>
+          <!--  tdf#73691
+                Translations of main menu keyboard ALT shortcuts can conflict with this assignment.
+                Those languages need to have blank assignments in order to avoid inheriting the en-US value.
+          -->
+          <value xml:lang="de"    install:module="unxwnt"></value>
+          <value xml:lang="vi"    install:module="unxwnt"></value>
         </prop>
       </node>
       <node oor:name="C_MOD2" oor:op="replace">