[WPS4R] No log output from R statements

[ridoo]

WPS logs do not contain R cat log statements. The following stacktrace is printed when running an R process:

2019-03-19 14:03:28,677 [pool-17-thread-2] WARN  org.n52.wps.server.r.util.RLogger: Could not log message 'cat("[WPS4R @ Mar 19, 2019 2:03:28 PM] New connection from WPS4R\n")'
org.rosuda.REngine.Rserve.RserveException: eval failed, request status: error code: 127
	at org.rosuda.REngine.Rserve.RConnection.eval(RConnection.java:234) ~[Rserve-1.7-3.jar:na]
	at org.n52.wps.server.r.FilteredRConnection.internalEval(FilteredRConnection.java:253) ~[52n-wps-r-4.0.0-beta.7-SNAPSHOT.jar:na]
	at org.n52.wps.server.r.FilteredRConnection.eval(FilteredRConnection.java:213) ~[52n-wps-r-4.0.0-beta.7-SNAPSHOT.jar:na]
	at org.n52.wps.server.r.util.RLogger.logIt(RLogger.java:78) [52n-wps-r-4.0.0-beta.7-SNAPSHOT.jar:na]
	at org.n52.wps.server.r.util.RLogger.logIt(RLogger.java:86) [52n-wps-r-4.0.0-beta.7-SNAPSHOT.jar:na]
	at org.n52.wps.server.r.util.RLogger.log(RLogger.java:73) [52n-wps-r-4.0.0-beta.7-SNAPSHOT.jar:na]
	at org.n52.wps.server.r.util.RConnector.getNewConnection(RConnector.java:71) [52n-wps-r-4.0.0-beta.7-SNAPSHOT.jar:na]
	at org.n52.wps.server.r.R_Config.openRConnection(R_Config.java:178) [52n-wps-r-4.0.0-beta.7-SNAPSHOT.jar:na]
	at org.n52.wps.server.r.GenericRProcess.run(GenericRProcess.java:196) [52n-wps-r-4.0.0-beta.7-SNAPSHOT.jar:na]
	at org.n52.wps.server.request.ExecuteRequestV100.call(ExecuteRequestV100.java:675) [52n-wps-server-4.0.0-beta.7-SNAPSHOT.jar:na]
	at org.n52.wps.server.request.ExecuteRequestV100.call(ExecuteRequestV100.java:96) [52n-wps-server-4.0.0-beta.7-SNAPSHOT.jar:na]
	at java.util.concurrent.FutureTask.run(FutureTask.java:266) [na:1.8.0_161]
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_161]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_161]
	at java.lang.Thread.run(Thread.java:748) [na:1.8.0_161]