copyright: update the year in --version, and use the standard hyphen

src/nano.c

@@ -915,10 +915,9 @@ void version(void)
 #else
     printf(_(" GNU nano, version %s\n"), VERSION);
 #endif
-    printf(" (C) 1999..2016 Free Software Foundation, Inc.\n");
-    printf(_(" (C) 2014..%s the contributors to nano\n"), "2017");
-    printf(
-	_(" Email: nano@nano-editor.org	Web: https://nano-editor.org/"));
+    printf(" (C) 1999-2011, 2013-2017 Free Software Foundation, Inc.\n");
+    printf(_(" (C) 2014-%s the contributors to nano\n"), "2017");
+    printf(_(" Email: nano@nano-editor.org	Web: https://nano-editor.org/"));
     printf(_("\n Compiled options:"));
 
 #ifdef NANO_TINY