Add nativeImage closure with args

These were recommended by @ilopmar in a comment
on micronaut-acme Issue 154:
micronaut-projects/micronaut-acme#154 (comment)

build.gradle

@@ -36,11 +36,17 @@ dependencies {
 application {
     mainClass.set("com.msgilligan.micronaut.acme.Application")
 }
+
 java {
     sourceCompatibility = JavaVersion.toVersion("11")
     targetCompatibility = JavaVersion.toVersion("11")
 }
 
+nativeImage {
+    args = [
+            '--initialize-at-run-time=io.netty.handler.ssl.OpenSsl,io.netty.handler.ssl.OpenSslPrivateKeyMethod,io.netty.internal.tcnative.CertificateVerifier,io.netty.internal.tcnative.SSL,io.netty.internal.tcnative.SSLPrivateKeyMethod'
+    ]
+}
 
 dockerBuild {
     images = ["${System.env.DOCKER_IMAGE ?: project.name}:$project.version"]