Bug 471020: Follow up, update quotes within security.properties. r=me

dom/locales/en-US/chrome/security/security.properties

@@ -77,4 +77,4 @@ WeakCipherSuiteWarning=This site uses the cipher RC4 for encryption, which is de
 # LOCALIZATION NOTE: Do not translate "X-Content-Type-Options: nosniff".
 MimeTypeMismatch=The resource from “%1$S” was blocked due to MIME type mismatch (X-Content-Type-Options: nosniff).
 # LOCALIZATION NOTE: Do not translate "X-Content-Type-Options and also do not trasnlate 'nosniff'
-XCTOHeaderValueMissing=X-Content-Type-Options header warning: value was “%1$S”; did you mean to send "nosniff"?
+XCTOHeaderValueMissing=X-Content-Type-Options header warning: value was “%1$S”; did you mean to send “nosniff”?