Fix some Typos and indents

Reviewed-by: Andy Polyakov <appro@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4108)

test/README.external

diff --git a/test/README.external b/test/README.external
index b4b011b..ab0f7c2 100644
--- a/test/README.external
+++ b/test/README.external
@@ -126,7 +126,7 @@
 
 $ VERBOSE=1 make TESTS=test_external_krb5 test
 
-Test failures supressions
+Test-failures suppressions
 -------------------------
 
 krb5 will automatically adapt its test suite to account for the configuration