respect system defaults (#95)

(cherry picked from commit 194d4b0)

Author: jonathanlukas

extension/java-client-operate/src/main/java/io/camunda/operate/auth/JwtAuthentication.java

@@ -46,7 +46,7 @@ public void resetToken() {
   }
 
   private TokenResponse retrieveToken() {
-    try (CloseableHttpClient client = HttpClients.createDefault()) {
+    try (CloseableHttpClient client = HttpClients.createSystem()) {
       HttpPost request = buildRequest();
       return client.execute(
           request,

extension/java-client-operate/src/main/java/io/camunda/operate/auth/SimpleAuthentication.java

@@ -28,7 +28,7 @@ public SimpleAuthentication(SimpleCredential simpleCredential) {
   }
 
   private SimpleAuthToken retrieveToken() {
-    try (CloseableHttpClient client = HttpClients.createDefault()) {
+    try (CloseableHttpClient client = HttpClients.createSystem()) {
       HttpPost request = buildRequest(simpleCredential);
       SimpleAuthToken simpleAuthToken =
           client.execute(

extension/spring-boot-starter-camunda-operate/src/main/java/io/camunda/operate/spring/OperateClientConfiguration.java

@@ -57,7 +57,7 @@ public CamundaOperateClientConfiguration operateClientConfiguration(
   @Bean("operateHttpClient")
   @ConditionalOnMissingBean(name = "operateHttpClient")
   public CloseableHttpClient operateHttpClient() {
-    return HttpClients.createDefault();
+    return HttpClients.createSystem();
   }
 
   @Bean