Fix NewlineAtEndOfFile check from CheckStyle on Windows.

See for details:
- yegor256/qulice#116
- yegor256/qulice@e1f047e#diff-0ac1133cfe7780870854ffd4c3f1d582R51

No functional changes.

Author: php-coder

src/main/config/checkstyle.xml

@@ -47,6 +47,11 @@
     <!-- See http://checkstyle.sourceforge.net/config_misc.html#NewlineAtEndOfFile -->
     <module name="NewlineAtEndOfFile">
         <property name="severity" value="warning"/>
+        <!--
+            Explicitly specify line separator that matches separator of the files.
+            We don't want to use a system-dependent separator because it won't work on Windows.
+        -->
+        <property name="lineSeparator" value="lf"/>
     </module>
 
     <!-- Checks that property files contain the same keys.                  -->