GH-1282 Make spring-webmvc dependency optional in AWS adapter

Resolves #1282

Author: olegz

spring-cloud-function-adapters/spring-cloud-function-adapter-aws/pom.xml

@@ -91,6 +91,7 @@
 		<dependency>
 		    <groupId>org.springframework</groupId>
 		    <artifactId>spring-webmvc</artifactId>
+			<optional>true</optional>
 		</dependency>
 		<dependency>
 			<groupId>org.springframework.cloud</groupId>