Revert "Switch to Quad114 as the default resolver"

This reverts commit 91f97833a3.

The Internet has become a sad place.

People in China need to use resolvers in China.
People in the US would not trust resolvers in China.
People in the EU would not trust resolvers in the US.

Revert to Quad9 for now, and add some documentation about why
that might be changed (especially in China) later.

dnscrypt-proxy/example-dnscrypt-proxy.toml

@@ -110,7 +110,7 @@ cert_refresh_delay = 240
 ## It will not be used if the configured system DNS works.
 ## A resolver supporting DNSSEC is recommended. This may become mandatory.
 
-fallback_resolver = '114.114.114.114:53'
+fallback_resolver = '9.9.9.9:53'
 
 
 ## Never try to use the system DNS settings; unconditionally use the

dnscrypt-proxy/xtransport.go

@@ -19,7 +19,7 @@ import (
 	"github.com/miekg/dns"
 )
 
-const DefaultFallbackResolver = "114.114.114.114:53"
+const DefaultFallbackResolver = "9.9.9.9:53"
 
 type CachedIPs struct {
 	sync.RWMutex