Found and fixed by Jasen Betts. No testcase for this as my usual text
editor insists on emitting only valid UTF-8.
+JH/32 Fix "tls_dhparam = none" under GnuTLS. At least with 3.7.9 this gave
+ a null-indirection SIGSEGV for the receive process.
+
+
Exim version 4.96
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