Improve deployment error message

14:54:36,076 ERROR [DeploymentPreprocessor] java.io.IOException: Could not create /opt/nuxeo-server-tomcat-9.1-SNAPSHOT/nxserver/nuxeo.war/ui/i18n/messages.json
java.io.IOException: Could not create /opt/nuxeo-server-tomcat-9.1-SNAPSHOT/nxserver/nuxeo.war/ui/i18n/messages.json
	at org.nuxeo.runtime.deployment.preprocessor.install.commands.AppendCommand.exec(AppendCommand.java:85)
	at org.nuxeo.runtime.deployment.preprocessor.install.CommandProcessorImpl.exec(CommandProcessorImpl.java:52)
	at org.nuxeo.runtime.deployment.preprocessor.DeploymentPreprocessor.predeploy(DeploymentPreprocessor.java:311)
	at org.nuxeo.runtime.deployment.preprocessor.DeploymentPreprocessor.predeploy(DeploymentPreprocessor.java:230)
	at org.nuxeo.runtime.deployment.preprocessor.DeploymentPreprocessor.main(DeploymentPreprocessor.java:595)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.nuxeo.runtime.tomcat.NuxeoDeployer.handleEvent(NuxeoDeployer.java:107)
	at org.nuxeo.runtime.tomcat.NuxeoDeployer.lifecycleEvent(NuxeoDeployer.java:58)
	at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:117)
	at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90)
	at org.apache.catalina.util.LifecycleBase.setStateInternal(LifecycleBase.java:394)
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:144)
	at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1572)
	at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1562)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:745)
Caused by: java.io.IOException: No such file or directory
	at java.io.UnixFileSystem.createFileExclusively(Native Method)
	at java.io.File.createNewFile(File.java:1012)
	at org.nuxeo.runtime.deployment.preprocessor.install.commands.AppendCommand.exec(AppendCommand.java:83)
	... 20 more
Done.
# Preprocessing done.