restrict proc-macro2 to version 1.0.86

Author: AdinAck

Cargo.lock

@@ -46,7 +46,7 @@ env_logger = { version = "0.11", optional = true }
 inflections = "1.1"
 log = { version = "~0.4", features = ["std"] }
 quote = "1.0"
-proc-macro2 = "1.0"
+proc-macro2 = "=1.0.86"
 anyhow = "1.0"
 thiserror = "1.0"
 serde = { version = "1.0", optional = true }