Make bindings always fill the whole status bar

Compute padding for key bindings in the status bar such that they use
all available space (without exceeding the given page size).

Signed-off-by: Lukas Fleischer <calcurse@cryptocrack.de>

src/keys.c

@@ -416,6 +416,8 @@ void
 keys_display_bindings_bar(WINDOW * win, int *bindings, int count,
 			  int page_base, int page_size)
 {
+	page_size = MIN(page_size, count - page_base);
+
 	/* Padding between two key bindings. */
 	const int padding =
 	    (col * 2) / page_size - (KEYS_KEYLEN + KEYS_LABELEN + 1);