Fix tracking issue RFC 2298 => rust-lang/rust#48075

Author: Centril

text/2298-macro-at-most-once-rep.md

@@ -1,7 +1,7 @@
 - Feature Name: `macro-at-most-once-rep`
 - Start Date: 2018-01-17
 - RFC PR: [rust-lang/rfcs#2298](https://github.com/rust-lang/rfcs/pull/2298)
-- Rust Issue: [rust-lang/rust#48591](https://github.com/rust-lang/rust/issues/48591)
+- Rust Issue: [rust-lang/rust#48075](https://github.com/rust-lang/rust/issues/48075)
 
 
 Summary