Fix Apache 2.0 license text

The Go package documentation website at go.pkg.dev only contains
packages that contain a known OSI approved license. The document
included in the oVirt SDK is missing the appendix, causing a large
enough difference percentage to mismatch.

The LICENSE file in this repository already contains the correct license
text (including the appendix), the LICENSE.txt file that is copied to
the SDK does not.

https://pkg.go.dev/github.com/ovirt/go-ovirt

https://pkg.go.dev/license-policy

https://pkg.go.dev/github.com/google/licensecheck

Signed-off-by: Vic Demuzere <[email protected]>

Author: sorcix

sdk/LICENSE.txt

@@ -1,4 +1,3 @@
-
                                  Apache License
                            Version 2.0, January 2004
                         http://www.apache.org/licenses/
@@ -175,3 +174,28 @@
       of your accepting any such warranty or additional liability.
 
    END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "{}"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright {yyyy} {name of copyright owner}
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.