AWSServiceConfiguration not copying maxRetryCount

In the copyWithZone function the the AWSServiceConfiguration only
copies the region type and credentials provider but not the retry
count. This causes the copy to always have a retry count of 0.

AWSCore/Service/AWSService.m

@@ -107,7 +107,7 @@ + (instancetype)configurationWithRegion:(AWSRegionType)regionType credentialsPro
 - (id)copyWithZone:(NSZone *)zone {
     AWSServiceConfiguration *configuration = [[[self class] allocWithZone:zone] initWithRegion:self.regionType
                                                                            credentialsProvider:self.credentialsProvider];
-
+    configuration.maxRetryCount = self.maxRetryCount;
     return configuration;
 }