Explicitly mark the license OR

Author: cuviper

Cargo.toml

@@ -5,7 +5,7 @@ documentation = "https://docs.rs/num-integer"
 homepage = "https://github.com/rust-num/num-integer"
 keywords = ["mathematics", "numerics"]
 categories = ["algorithms", "science", "no-std"]
-license = "MIT/Apache-2.0"
+license = "MIT OR Apache-2.0"
 repository = "https://github.com/rust-num/num-integer"
 name = "num-integer"
 version = "0.1.43"