Bug 1502667 - Port bug 1050329 part 2 to TB: Add error string for h2 GOAWAY. r=aceman

--HG--
extra : rebase_source : 86be7a2cff1523228c64db890515de0ac7f93077

mail/locales/en-US/chrome/overrides/netError.dtd

@@ -195,3 +195,6 @@ functionality specific to thunderbird. -->
 <!ENTITY inadequateSecurityError.longDesc "<p><span class='hostname'></span> uses security technology that is outdated and vulnerable to attack. An attacker could easily reveal information which you thought to be safe. The website administrator will need to fix the server first before you can visit the site.</p><p>Error code: NS_ERROR_NET_INADEQUATE_SECURITY</p>">
 
 <!ENTITY blockedByPolicy.title "Blocked Page">
+
+<!ENTITY networkProtocolError.title "Network Protocol Error">
+<!ENTITY networkProtocolError.longDesc "<p>The page you are trying to view cannot be shown because an error in the network protocol was detected.</p><ul><li>Please contact the website owners to inform them of this problem.</li></ul>">