Upgrade lru to v0.15

Author: paolobarbolini

Cargo.toml

@@ -20,7 +20,7 @@ futures-core = "0.3"
 futures-util = "0.3"
 futures-sink = "0.3"
 keyed_priority_queue = "0.4"
-lru = "0.14.0"
+lru = "0.15.0"
 mysql_common = { version = "0.35.4", default-features = false }
 pem = "3.0"
 percent-encoding = "2.1.0"