Upgrade to HtmlUnit 2.25

Fixes spring-projectsgh-8515

Author: philwebb

spring-boot-dependencies/pom.xml

@@ -89,7 +89,7 @@
 		<hibernate-validator.version>5.4.0.Final</hibernate-validator.version>
 		<hikaricp.version>2.5.1</hikaricp.version>
 		<hsqldb.version>2.3.3</hsqldb.version>
-		<htmlunit.version>2.24</htmlunit.version>
+		<htmlunit.version>2.25</htmlunit.version>
 		<httpasyncclient.version>4.1.3</httpasyncclient.version>
 		<httpclient.version>4.5.3</httpclient.version>
 		<httpcore.version>4.4.6</httpcore.version>