create log4j logfile only when required (#262)

Co-authored-by: Pitterling

Author: Pitterling

src/main/resources/log4j2.xml

@@ -4,7 +4,7 @@
         <Console name="Console" target="SYSTEM_OUT">
             <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
         </Console>
-        <File name="MyFile" fileName="ksar_all.log" immediateFlush="true" append="false">
+        <File name="MyFile" fileName="ksar_all.log" immediateFlush="true" append="false" createOnDemand="true">
             <PatternLayout pattern="%d{yyy-MM-dd HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
         </File>
     </appenders>