Upgrade log4j dependency to version 1.2.17

Upgrade to the latest stable release of log4j. The previous 'jms'
and 'jmx' exclusions are not longer required since these have now
been marked as optional dependencies in the upstream POM.

build.gradle

@@ -165,13 +165,7 @@ project("spring-core") {
 			optional dep
 			exclude group: "org.apache.ant", module: "ant"
 		}
-		compile("log4j:log4j:1.2.15") { dep ->
-			optional dep
-			exclude group: "javax.mail", module: "mail"
-			exclude group: "javax.jms", module: "jms"
-			exclude group: "com.sun.jdmk", module: "jmxtools"
-			exclude group: "com.sun.jmx", module: "jmxri"
-		}
+		compile("log4j:log4j:1.2.17", optional)
 		testCompile("xmlunit:xmlunit:1.2")
 		testCompile("org.codehaus.woodstox:wstx-asl:3.2.7")
 	}
@@ -610,12 +604,7 @@ project("spring-test-mvc") {
 		testCompile("org.slf4j:slf4j-log4j12:${slf4jVersion}") {
 			exclude group: "log4j", module: "log4j"
 		}
-		testCompile("log4j:log4j:1.2.15") {
-			exclude group: "javax.mail", module: "mail"
-			exclude group: "javax.jms", module: "jms"
-			exclude group: "com.sun.jdmk", module: "jmxtools"
-			exclude group: "com.sun.jmx", module: "jmxri"
-		}
+		testCompile("log4j:log4j:1.2.17")
 		testCompile("javax.servlet:jstl:1.2")
 		testCompile("org.hibernate:hibernate-validator:4.3.0.Final")
 		testCompile("org.codehaus.jackson:jackson-mapper-asl:1.4.2")