Give proper error message when 'internal' folder can't be found.

source/ide/wiki/wiki_global.bas

@@ -1,5 +1,6 @@
 DIM SHARED Cache_Folder AS STRING
 Cache_Folder$ = "internal\help"
+IF _DIREXISTS("internal") = 0 THEN GOTO NoInternalFolder
 IF _DIREXISTS(Cache_Folder$) = 0 THEN MKDIR Cache_Folder$
 DIM SHARED Help_sx, Help_sy, Help_cx, Help_cy
 DIM SHARED Help_Select, Help_cx1, Help_cy1, Help_SelX1, Help_SelX2, Help_SelY1, Help_SelY2

source/qb64.bas

@@ -65,6 +65,7 @@ IF _FILEEXISTS("refactor.txt") THEN
     CLOSE fh
 END IF
 
+NoInternalFolder:
 IF _DIREXISTS("internal") = 0 THEN
     _SCREENSHOW
     PRINT "QB64 cannot locate the 'internal' folder"