Small language improvements

wiki/src/doc/about/openpgp_keys/signing_key_revocation.mdwn

@@ -126,13 +126,13 @@ who are in possession of the cryptographic material.
 
 We are proposing this to you because we trust in both your technical
 abilities to store your share in a safe place and manipulate it as
-required but also because we trust in you as a human being to make
+required. But also because we trust you as a human being to make
 informed judgment on when to use your share and act only in the
 interest of Tails.
 
 The bad things that could happen if the mechanism fails are:
 
-A. The signing key is not revoked while it should be. This could allow
+A. The signing key is not revoked when it should be. This could allow
 possible attackers to distribute malicious Tails images or publish
 malicious information on our name.