Bump ant from 1.9.6 to 1.9.15 (#2483)

pom.xml

@@ -295,7 +295,7 @@
 					<dependency>
 						<groupId>org.apache.ant</groupId>
 						<artifactId>ant</artifactId>
-						<version>1.9.6</version>
+						<version>1.9.15</version>
 					</dependency>
 				</dependencies>
 				<configuration>