Remove unused French translations in Connect engine (#2252)

These files are currently not being used nor compiled in MariaDB. The
use of large lists of 'case' statements in these source files are also
not a great way to represent translated strings. This git history can
be referred to when a better translation interface can be implemented
in the future.

Therefore, these files can be removed to cleanup the MariaDB codebase.

All new code of the whole pull request, including one or several files
that are either new files or modified ones, are contributed under the
BSD-new license. I am contributing on behalf of my employer
Amazon Web Services, Inc.

storage/connect/ha_connect.cc

@@ -540,11 +540,7 @@ extern "C" const char *msglang(void)
 #else   // !XMSG && !NEWMSG
 extern "C" const char *msglang(void)
 {
-#if defined(FRENCH)
-  return "french";
-#else  // DEFAULT
   return "english";
-#endif // DEFAULT
 } // end of msglang
 #endif  // !XMSG && !NEWMSG
 

storage/connect/messages.h

@@ -1,13 +1,5 @@
 /**************************************************************************/
 /*  NLS messsages definition.                                             */
 /**************************************************************************/
-#if defined(FRENCH)
-#if defined(CPX)
-#include "frmsg1.h"
-#else   /* not CPX */
-#include "frmsg2.h"
-#endif  /* CPX */
-#else   /* not FRENCH */
 #include "engmsg.h"
-#endif  /* FRENCH */
 /* ---------------------------------------------------------------------- */

storage/connect/plgdbsem.h

@@ -14,11 +14,7 @@
 /***********************************************************************/
 /*  DB Constant definitions.                                           */
 /***********************************************************************/
-#if defined(FRENCH)
-#define DEFAULT_LOCALE  "French"
-#else   // !FRENCH
 #define DEFAULT_LOCALE  "English"
-#endif  // !FRENCH
 
 #define DOS_MAX_PATH    144   /* Must be the same across systems       */
 #define DOS_BUFF_LEN    100   /* Number of lines in binary file buffer */

storage/connect/rcmsg.c

@@ -32,17 +32,6 @@ const char *GetMsgid(int id)
   const char *p = NULL;
 
   // This conditional until a real fix is found for MDEV-7304
-#if defined(FRENCH)
-  if (!stricmp(msglang(), "french"))
-    switch (id) {
-#include "frids.h"
-#if defined(NEWMSG)
-#include "frcas.h"
-#endif   // NEWMSG
-    } // endswitch(id)
-
-  else    // English
-#endif   // FRENCH
     switch (id) {
 #include "enids.h"
 #if defined(NEWMSG)