Remove postgres startup workaround in undertow, update dependencies (#3407)

The workaround should now be unnecessary because of this commit:
https://github.com/TechEmpower/FrameworkBenchmarks/commit/5f440da97c4053e0c679793b7fc928e59f70c990

frameworks/Java/undertow/pom.xml

@@ -13,14 +13,14 @@
     <maven.compiler.source>9</maven.compiler.source>
     <maven.compiler.target>9</maven.compiler.target>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-    <hikaricp.version>2.7.7</hikaricp.version>
+    <hikaricp.version>2.7.8</hikaricp.version>
     <jackson.version>2.9.4</jackson.version>
     <maven-shade-plugin.version>3.1.0</maven-shade-plugin.version>
     <mongodb.version>3.6.3</mongodb.version>
     <mustache.version>0.9.5</mustache.version>
-    <mysql.version>5.1.45</mysql.version>
+    <mysql.version>5.1.46</mysql.version>
     <postgresql.version>42.2.1</postgresql.version>
-    <undertow.version>1.4.22.Final</undertow.version>
+    <undertow.version>2.0.1.Final</undertow.version>
     <versions-maven-plugin.version>2.4</versions-maven-plugin.version>
   </properties>
 

frameworks/Java/undertow/src/main/java/hello/HelloWebServer.java

@@ -167,20 +167,7 @@ public final class HelloWebServer {
       config.setUsername(username);
       config.setPassword(password);
       config.setMaximumPoolSize(connections);
-      // Attempt to work around "FATAL: the database system is starting up"
-      // error seen in Travis+Docker+PostgreSQL environment.
-      for (int i = 0;;) {
-        try {
-          return new HikariDataSource(config);
-        } catch (com.zaxxer.hikari.pool.HikariPool.PoolInitializationException e) {
-          if (++i >= 10) throw e;
-          try {
-            Thread.sleep(1000);
-          } catch (InterruptedException e2) {
-            Thread.currentThread().interrupt();
-          }
-        }
-      }
+      return new HikariDataSource(config);
     }
 
     /**