Fix typos in compiler/rustc_error_codes/src/error_codes/E0711.md

Author: BorisNaum

compiler/rustc_error_codes/src/error_codes/E0711.md

@@ -22,8 +22,8 @@ fn foo_unstable() {}
 ```
 
 In the above example, the `foo` feature is first defined to be stable since
-1.0.0, but is then re-declared stable since 1.29.0. This discrepancy in
-versions causes an error. Furthermore, `foo` is then re-declared as unstable,
+1.0.0, but is then redeclared stable since 1.29.0. This discrepancy in
+versions causes an error. Furthermore, `foo` is then redeclared as unstable,
 again the conflict causes an error.
 
 This error can be fixed by splitting the feature, this allows any