Don't allow --enable-selftest on non-FIPS builds

It probably won't compile anyway.

Author: LinuxJedi

configure.ac

@@ -6602,6 +6602,9 @@ AS_CASE([$ENABLED_SELFTEST],
         SELFTEST_VERSION="v1"
     ])
 
+AS_IF([test "x$ENABLED_SELFTEST" = "xyes" && test "x$ENABLED_FIPS" = "xno"],
+    [AC_MSG_ERROR([--enable-selftest requires --enable-fips])])
+
 AS_CASE([$SELFTEST_VERSION],
     ["v2"],[
         AM_CFLAGS="$AM_CFLAGS -DHAVE_SELFTEST -DHAVE_SELFTEST_VERSION=2 -DHAVE_PUBLIC_FFDHE"