Removed wrong imports

Author: marcingrzejszczak

spring-cloud-sleuth-stream/src/test/java/org/springframework/cloud/sleuth/stream/TraceIgnoringChannelInterceptorTests.java

@@ -26,8 +26,6 @@
 import org.junit.runner.RunWith;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
-import org.springframework.boot.test.context.SpringBootTest;
-import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
 import org.springframework.cloud.sleuth.Sampler;
 import org.springframework.cloud.sleuth.Span;
 import org.springframework.cloud.sleuth.Tracer;