Upgrade to Gradle 4.4.1 (and Netty 4.1.19)

Issue: SPR-16237

build.gradle

@@ -52,7 +52,7 @@ configure(allprojects) { project ->
 	ext.junitVintageVersion  = "4.12.2"
 	ext.kotlinVersion        = "1.2.10"
 	ext.log4jVersion         = "2.10.0"
-	ext.nettyVersion         = "4.1.18.Final"
+	ext.nettyVersion         = "4.1.19.Final"
 	ext.reactorVersion       = "Bismuth-SR4"
 	ext.rxjavaVersion        = "1.3.4"
 	ext.rxjavaAdapterVersion = "1.2.1"
@@ -274,7 +274,7 @@ configure(rootProject) {
 
 	task wrapper(type: Wrapper) {
 		description = "Generates gradlew[.bat] scripts"
-		gradleVersion = '4.4'
+		gradleVersion = '4.4.1'
 
 		doLast() {
 			def gradleOpts = "-XX:MaxMetaspaceSize=1024m -Xmx1024m"

gradle/wrapper/gradle-wrapper.properties

@@ -2,4 +2,4 @@ distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.4-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.4.1-bin.zip