RMB-1005: Unset DB_ env fixing Failed to resolve 'myhost'

https://folio-org.atlassian.net/browse/RMB-1005

Author: julianladisch

domain-models-runtime/src/test/java/org/folio/rest/persist/PostgresClientWithAsyncReadConnTest.java

@@ -12,25 +12,30 @@ public class PostgresClientWithAsyncReadConnTest {
 
   @Test
   public void getInstanceTest() {
-    Envs.setEnv(Map.of(
-        "DB_HOST_READER_ASYNC", "myhost_reader_async",
-        "DB_PORT_READER_ASYNC", "54321",
-        "DB_HOST_READER", "myhost_reader",
-        "DB_PORT_READER", "12345",
-        "DB_HOST", "myhost",
-        "DB_PORT", "5433",
-        "DB_USERNAME", "myuser",
-        "DB_PASSWORD", "mypassword",
-        "DB_DATABASE", "mydatabase",
-        "DB_CONNECTIONRELEASEDELAY", "1000"
-    ));
-    var vertx = Vertx.vertx();
-    var tenant = "testTenant";
-    var client = PostgresClientWithAsyncReadConn.getInstance(vertx, tenant);
-    var initializer = client.getPostgresClientInitializer();
-    assertNotNull(client);
-    assertNotNull(client.getReaderClient());
-    assertNotEquals(client.getClient(), client.getReaderClient());
-    assertEquals(client.getReaderClient(), initializer.getAsyncReadClient());
+    try {
+      Envs.setEnv(Map.of(
+          "DB_HOST_READER_ASYNC", "myhost_reader_async",
+          "DB_PORT_READER_ASYNC", "54321",
+          "DB_HOST_READER", "myhost_reader",
+          "DB_PORT_READER", "12345",
+          "DB_HOST", "myhost",
+          "DB_PORT", "5433",
+          "DB_USERNAME", "myuser",
+          "DB_PASSWORD", "mypassword",
+          "DB_DATABASE", "mydatabase",
+          "DB_CONNECTIONRELEASEDELAY", "1000"
+      ));
+      var vertx = Vertx.vertx();
+      var tenant = "testTenant";
+      var client = PostgresClientWithAsyncReadConn.getInstance(vertx, tenant);
+      var initializer = client.getPostgresClientInitializer();
+      assertNotNull(client);
+      assertNotNull(client.getReaderClient());
+      assertNotEquals(client.getClient(), client.getReaderClient());
+      assertEquals(client.getReaderClient(), initializer.getAsyncReadClient());
+    } finally {
+      // restore defaults
+      Envs.setEnv(System.getenv());
+    }
   }
 }