Update to Spring Boot 1.5.16.RELEASE

Fixes: gh-5975

gradle/javaprojects.gradle

@@ -36,7 +36,7 @@ ext.springDataCommonsVersion = '1.13.14.RELEASE'
 ext.springDataJpaVersion = '1.11.12.RELEASE'
 ext.springDataRedisVersion = '1.8.12.RELEASE'
 ext.springSessionVersion = '1.3.2.RELEASE'
-ext.springBootVersion = '1.5.15.RELEASE'
+ext.springBootVersion = '1.5.16.RELEASE'
 ext.thymeleafVersion = '3.0.9.RELEASE'
 ext.jsonassertVersion = '1.4.0'
 ext.validationApiVersion = '1.1.0.Final'