Add default buffer connectionRetryTimeout to avoid literal immediate timeouts

Motivation:

When trying to allow users to configure the connection retry timeout offset,
not having a value provided (deadline of `now`) caused all attempts to use the pool to fail.

Modifications:

- Change: RedisConnectionPool to always have a timeout offset defined

Result:

If users don't specify any value, then the default of 60 seconds will be used.

If users specify "nil" (or `.none`) as the timeout, then a minimum of 10 milliseconds will be used to avoid immediate timeouts

Otherwise, use the user's specified `TimeAmount` as the offset of the timeout

Sources/RediStack/RedisConnectionPool.swift

@@ -45,7 +45,7 @@ public class RedisConnectionPool {
     /// This needs to be a var because we reuse the same connection
     private var pubsubConnection: RedisConnection?
 
-    private let connectionRetryTimeout: TimeAmount?
+    private let connectionRetryTimeout: TimeAmount
     private let connectionPassword: String?
     private let connectionSystemContext: Logger
     private let poolSystemContext: Context
@@ -88,7 +88,7 @@ public class RedisConnectionPool {
         self.loop = loop
         self.serverConnectionAddresses = ConnectionAddresses(initialAddresses: serverConnectionAddresses)
         self.connectionPassword = connectionPassword
-        self.connectionRetryTimeout = connectionRetryTimeout
+        self.connectionRetryTimeout = connectionRetryTimeout ?? .milliseconds(10)
         
         // mix of terminology here with the loggers
         // as we're being "forward thinking" in terms of the 'baggage context' future type
@@ -392,11 +392,7 @@ extension RedisConnectionPool: RedisClientWithUserContext {
         let logger = self.prepareLoggerForUse(context)
         
         guard let connection = preferredConnection else {
-            return pool
-                .leaseConnection(
-                    deadline: self.connectionRetryTimeout.map({ .now() + $0 }) ?? .now(),
-                    logger: logger
-                )
+            return pool.leaseConnection(deadline: .now() + self.connectionRetryTimeout, logger: logger)
                 .flatMap { operation($0, pool.returnConnection(_:logger:), logger) }
         }