fix tests

ozgcloud-common-lib/src/test/java/de/ozgcloud/common/grpc/GrpcUtilTest.java

@@ -63,14 +63,14 @@ class GrpcUtilTest {
 			void shouldReadFromHeader() {
 				var value = GrpcUtil.getFromHeaders(KEY_VALUE_BIN, header);
 
-				assertThat(value).isEqualTo(TEST_VALUE);
+				assertThat(value).contains(TEST_VALUE);
 			}
 
 			@Test
 			void shouldReturnNullOnUnknownKey() {
 				var value = GrpcUtil.getFromHeaders(UNKNOWN_KEY_BIN, header);
 
-				assertThat(value).isNull();
+				assertThat(value).isEmpty();
 			}
 		}