Use correct method to write error message in JSP

[labkey-tchad]

Rationale

LabKeyJspWriter complains if you call out.print.

java.lang.IllegalStateException: A JSP is attempting to render a string! '<p>Error rendering graph</p>' For help rectifying this problem, review this page https://www.labkey.org/Documentation/26.3/wiki-page.view?name=premServerEncoding&referrer=inPage or contact your LabKey Account Manager.
	at org.labkey.api.jsp.LabKeyJspWriter.throwException(LabKeyJspWriter.java:77)
	at org.labkey.api.jsp.LabKeyJspWriter.print(LabKeyJspWriter.java:54)
	at org.labkey.jsp.compiled.org.labkey.experiment.controllers.exp.experimentRunGraphView_jsp._jspService(experimentRunGraphView_jsp.java:219)

out.write does what we want.

Additionally. While the above error was useful for flagging this JSP issue, an empty graph shouldn't be throwing an exception.

Related Pull Requests

• Replace Graphviz/DOT with a Java implementation #7557

Changes

• Use correct method to write error message in JSP
• Don't throw an exception if the graph is empty
• Log errors thrown when converting graph to SVG