Update to Spring Boot 1.5.22.RELEASE

Fixes gh-7947

Author: rwinch

gradle/javaprojects.gradle

@@ -36,7 +36,7 @@ ext.springDataCommonsVersion = '1.13.23.RELEASE'
 ext.springDataJpaVersion = '1.11.23.RELEASE'
 ext.springDataRedisVersion = '1.8.23.RELEASE'
 ext.springSessionVersion = '1.3.5.RELEASE'
-ext.springBootVersion = '1.5.16.RELEASE'
+ext.springBootVersion = '1.5.22.RELEASE'
 ext.thymeleafVersion = '3.0.9.RELEASE'
 ext.jsonassertVersion = '1.4.0'
 ext.validationApiVersion = '1.1.0.Final'