Fix invalid XML comment in efl_mono.dll.config

Use <!-- and --> to comment the license files

Reviewed-by: João Paulo Taylor Ienczak Zanette <joao.tiz@expertisesolutions.com.br>
Differential Revision: https://phab.enlightenment.org/D10790

src/bindings/mono/efl_mono.dll.config.in

@@ -1,3 +1,4 @@
+<!--
 /*
  * Copyright 2019 by its authors. See AUTHORS.
  *
@@ -13,6 +14,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+-->
 <configuration>
   <dllmap dll="eina" target="@EINA@"/>
   <dllmap dll="efl" target="@EFL@"/>