Fix springloaded co-ordinates

Apparently springloaded 1.1.5 was released to Maven Central with a
different groupId than to repo.spring.io. It would have worked in
milestones because the repository was declared.

See gh-648

spring-boot-samples/spring-boot-sample-web-ui/build.gradle

@@ -13,7 +13,7 @@ buildscript {
 	}
 	dependencies {
 		classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
-		classpath("org.springsource.loaded:springloaded:${springLoadedVersion}")
+		classpath("org.springframework:springloaded:${springLoadedVersion}")
 	}
 }