Acra: don't include email prefix.

We've recently started getting exceptions such as:
"java.lang.ClassCastException: java.lang.String cannot be cast to java.util.ArrayList"

I suspect it may be related to using the new email body prefix which is
probably not as well tested upstream as the rest of the code. Removing
it to see if this fixes things.

app/src/main/java/com/etesync/syncadapter/AcraConfiguration.java

@@ -18,7 +18,6 @@ public class AcraConfiguration {
         builder.getPluginConfigurationBuilder(MailSenderConfigurationBuilder.class)
                 .setMailTo("reports@etesync.com")
                 .setResSubject(R.string.crash_email_subject)
-                .setResBody(R.string.crash_email_body)
                 .setReportFileName("ACRA-report.stacktrace.json")
                 .setReportAsFile(emailSupportsAttachments(context))
                 .setEnabled(true);