Remove configuration-properties plugin

The webflux-test module only has manual metadata so we shouldn't use
the plugin as it kicks of the annotation processor and that doesn't
generate anything.

Author: snicoll

module/spring-boot-webflux-test/build.gradle

@@ -16,7 +16,6 @@
 
 plugins {
 	id "java-library"
-	id "org.springframework.boot.configuration-properties"
 	id "org.springframework.boot.deployed"
 	id "org.springframework.boot.optional-dependencies"
 	id "org.springframework.boot.test-slice"