Change BWC version for settings serialization to 6.1.0

relates 41925e1
relates #26878

Author: danielmitterdorfer

core/src/test/java/org/elasticsearch/common/settings/SettingsTests.java

@@ -729,7 +729,7 @@ public void testMissingValue() throws Exception {
 
     public void testReadLegacyFromStream() throws IOException {
         BytesStreamOutput output = new BytesStreamOutput();
-        output.setVersion(VersionUtils.getPreviousVersion(Version.CURRENT));
+        output.setVersion(VersionUtils.getPreviousVersion(Version.V_6_1_0));
         output.writeVInt(5);
         output.writeString("foo.bar.1");
         output.writeOptionalString("1");
@@ -742,7 +742,7 @@ public void testReadLegacyFromStream() throws IOException {
         output.writeString("foo.bar.baz");
         output.writeOptionalString("baz");
         StreamInput in = StreamInput.wrap(BytesReference.toBytes(output.bytes()));
-        in.setVersion(VersionUtils.getPreviousVersion(Version.CURRENT));
+        in.setVersion(VersionUtils.getPreviousVersion(Version.V_6_1_0));
         Settings settings = Settings.readSettingsFromStream(in);
         assertEquals(2, settings.size());
         assertEquals(Arrays.asList("0", "1", "2", "3"), settings.getAsList("foo.bar"));