hg4idea: internal merge for tests

plugins/hg4idea/testData/repo/dot_hg/hgrc

@@ -1,2 +1,5 @@
 [ui]
 username = John Doe <John.Doe@example.com>
+
+[merge-patterns]
+** = internal:merge

plugins/hg4idea/testSrc/hg4idea/test/repo/HgRealRepositoryReaderTest.java

@@ -44,7 +44,7 @@ public class HgRealRepositoryReaderTest extends HgPlatformTest {
   }
 
   public void testMergeState() {
-    hg("merge --tool internal:merge branchB");
+    hg("merge branchB");
     assertEquals(myRepositoryReader.readState(), Repository.State.MERGING);
   }
 
@@ -60,7 +60,6 @@ public class HgRealRepositoryReaderTest extends HgPlatformTest {
     TestRepositoryUtil.assertEqualCollections(myRepositoryReader.readBranches(), Arrays.asList("default", "branchA", "branchB"));
   }
 
-
   private void createBranches() {
     cd(myRepository);
     String aFile = "A.txt";