tweaks: remove the now-unused meta flag from 'keystruct'

src/global.c

@@ -531,7 +531,6 @@ int keycode_from_string(const char *keystring)
 void assign_keyinfo(keystruct *s, const char *keystring, const int keycode)
 {
 	s->keystr = keystring;
-	s->meta = ((keystring[0] == 'M' || keystring[0] == 'S') && keycode < 0x7F);
 	s->keycode = (keycode ? keycode : keycode_from_string(keystring));
 }
 

src/nano.h

@@ -422,8 +422,6 @@ typedef struct rcoption {
 typedef struct keystruct {
 	const char *keystr;
 		/* The string that describes the keystroke, like "^C" or "M-R". */
-	bool meta;
-		/* Whether this is a Meta keystroke. */
 	int keycode;
 		/* The integer that, together with meta, identifies the keystroke. */
 	int menus;