Bump spring-webmvc from 4.3.2.RELEASE to 5.3.18

Bumps [spring-webmvc](https://github.com/spring-projects/spring-framework) from 4.3.2.RELEASE to 5.3.18.
- [Release notes](https://github.com/spring-projects/spring-framework/releases)
- [Commits](spring-projects/spring-framework@v4.3.2.RELEASE...v5.3.18)

---
updated-dependencies:
- dependency-name: org.springframework:spring-webmvc
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

pom.xml

@@ -15,7 +15,7 @@
         <maven.compiler.target>1.8</maven.compiler.target>
 
         <weixin-java-mp.version>4.2.0</weixin-java-mp.version>
-        <spring.version>4.3.2.RELEASE</spring.version>
+        <spring.version>5.3.18</spring.version>
         <spring-security.version>4.2.17.RELEASE</spring-security.version>
         <guava.version>29.0-jre</guava.version>
         <slf4j.version>1.7.24</slf4j.version>