Revert "Make it possible to disable fuzz testing"

This reverts commit eb40eaed72.

Reviewed-by: Emilia Käsper <emilia@openssl.org>

Configure

@@ -342,7 +342,6 @@ my @disablables = (
     "filenames",
     "fuzz-libfuzzer",
     "fuzz-afl",
-    "fuzz-test",
     "gost",
     "heartbeats",
     "hw(-.+)?",

test/recipes/05-test_fuzz.t

@@ -15,9 +15,6 @@ use OpenSSL::Test::Utils;
 
 setup("test_fuzz");
 
-plan skip_all => "Fuzz testing is disabled by this OpenSSL build"
-    if disabled("fuzz-test");
-
 my @fuzzers = ('asn1', 'asn1parse', 'bignum', 'bndiv', 'conf', 'crl', 'server', 'x509');
 if (!disabled("cms")) {
     push @fuzzers, 'cms';