fix bug 64562 Some chrome dtd bugs [duplicate entities in dtds]

fixes from cjh@kr.freebsd.org r=jag, sr=jst

editor/ui/composer/locale/en-US/editorOverlay.dtd

@@ -538,7 +538,6 @@
 <!ENTITY testDocumentCmd.label "Test Document">
 <!ENTITY showEmbeddedCmd.label "Show Embedded Objects">
 <!ENTITY dumpContentCmd.label "Dump Content Tree">
-<!ENTITY testDocumentCmd.label "Test Document">
 <!ENTITY runUnitTestsCmd.label "Run Unit Tests">
 <!ENTITY startLogCmd.label "Start Log">
 <!ENTITY stopLogCmd.label "Stop Log">

mailnews/base/prefs/resources/locale/en-US/pref-viewing_messages.dtd

@@ -29,7 +29,6 @@ Rights Reserved.
 <!ENTITY boldItalic.label                 "Bold Italic">
 <!ENTITY size.label                       "Size:">
 <!ENTITY size.accesskey                   "s">
-<!ENTITY regular.label                    "Regular">
 <!ENTITY bigger.label                     "Bigger">
 <!ENTITY smaller.label                    "Smaller">
 <!ENTITY color.label                      "Color:">

mailnews/compose/resources/locale/en-US/messengercompose.dtd

@@ -155,7 +155,6 @@
 <!ENTITY testDocumentCmd.label "Test Document">
 <!ENTITY showEmbeddedCmd.label "Show Embedded Objects">
 <!ENTITY dumpContentCmd.label "Dump Content Tree">
-<!ENTITY testDocumentCmd.label "Test Document">
 <!ENTITY runUnitTestsCmd.label "Run Unit Tests">
 <!ENTITY startLogCmd.label "Start Log">
 <!ENTITY stopLogCmd.label "Stop Log">