fix src/meson.build

src/meson.build

@@ -20,8 +20,7 @@ if not cpp_compiler.has_header('FlexLexer.h')
          fs.parent(fs.parent(flex_exe.full_path())) / 'include' / 'FlexLexer.h', 
          'FlexLexer.h'
          )
-#  flexlexer_h = '../../src/FlexLexer.h'
-  flexlexer_h = 'FlexLexer.h'
+  flexlexer_h = []	
 else
   flexlexer_h = []
 endif