Update to spring-build-conventions:0.0.15.RELEASE

Fixes: gh-5048

build.gradle

@@ -1,6 +1,6 @@
 buildscript {
 	dependencies {
-		classpath 'io.spring.gradle:spring-build-conventions:0.0.13.RELEASE'
+		classpath 'io.spring.gradle:spring-build-conventions:0.0.15.RELEASE'
 		classpath "org.springframework.boot:spring-boot-gradle-plugin:$springBootVersion"
 	}
 	repositories {