Set HOME and USERNAME environment vars. #3913

It seems like this didn't used to be necessary, Adam
should see if jsvc is somehow responsible.

@@ -43,7 +43,11 @@ public class LibreOfficeRenderer {
             UtilIO.writeString(outputFile, output);
 
             List<String> args = Arrays.asList(new String[]{"libreoffice", "--headless", "--convert-to", "pdf", outputFile.getPath(), "--outdir", "/tmp"});
-            Process process = new ProcessBuilder(args).start();
+            ProcessBuilder pb = new ProcessBuilder(args);
+            Map env = pb.environment();
+            env.put("HOME", "/home/ofbiz");
+            env.put("USERNAME", "ofbiz");
+            Process process = pb.start();
             InputStream is = process.getInputStream();
             process.waitFor();