EXTENSION_INSTALLED were never used

Source commit: 4090606381074c2fde86cddf684ed11277cc3a33

source/resource/TextsWin.h

@@ -580,7 +580,6 @@
 #define CHECK_FOR_UPDATES_TITLE 1972
 #define ADD_EXTENSION_CAPTION   1973
 #define ADD_EXTENSION_PROMPT    1974
-#define EXTENSION_INSTALLED     1975
 #define EXTENSION_OPTIONS_CAPTION 1976
 #define EXTENSION_OPTIONS_BROWSE 1977
 #define EXTENSION_OPTIONS_BROWSE_TITLE 1978

source/resource/TextsWin1.rc

@@ -583,7 +583,6 @@ BEGIN
         CHECK_FOR_UPDATES_TITLE, "Check for Updates"
         ADD_EXTENSION_CAPTION, "Add Extension"
         ADD_EXTENSION_PROMPT, "Enter URL or path to the &extension:"
-        EXTENSION_INSTALLED, "Extension was installed. Please restart WinSCP."
         EXTENSION_OPTIONS_CAPTION, "Options for extension '%s'"
         EXTENSION_OPTIONS_BROWSE, "Browse..."
         EXTENSION_OPTIONS_BROWSE_TITLE, "Select '%s'"