__matrix_synapse: add --enable-3pid-lookups flag, normalize indentation

type/__matrix_synapse/files/homeserver.yaml.sh

@@ -1334,7 +1334,7 @@ fi
 cat << EOF
 # Enable 3PIDs lookup requests to identity servers from this server.
 #
-#enable_3pid_lookup: true
+enable_3pid_lookup: ${ENABLE_3PID_LOOKUPS:?}
 
 # If set, allows registration of standard or admin accounts by anyone who
 # has the shared secret, even if registration is otherwise disabled.

type/__matrix_synapse/man.rst

@@ -239,6 +239,9 @@ allow-public-rooms-without-auth
 enable-server-notices
   Enable the server notices room.
 
+enable-3pid-lookups
+  Enable 3PIDs lookup requests to identity servers from this server.
+
 allow-guest-access
   Allows users to register as guests without a password/email/etc, and
   participate in rooms hosted on this server which have been made accessible

type/__matrix_synapse/manifest

@@ -223,6 +223,12 @@ if [ -f "$__object/parameter/default-identity-server" ]; then
 	export DEFAULT_IDENTITY_SERVER
 fi
 
+ENABLE_3PID_LOOKUPS='false'
+if [ -f "$__object/parameter/enable-3pid-lookup" ]; then
+	ENABLE_3PID_LOOKUPS='true'
+fi
+export ENABLE_3PID_LOOKUPS
+
 # Federation.
 ALLOW_PUBLIC_ROOMS_OVER_FEDERATION=$(get_boolean_for 'allow-public-room-over-federation')
 ALLOW_PUBLIC_ROOMS_WITHOUT_AUTH=$(get_boolean_for 'allow-public-rooms-without-auth')

type/__matrix_synapse/parameter/boolean

@@ -17,3 +17,4 @@ user-directory-search-all-users
 enable-message-retention-policy
 worker-mode
 enable-url-preview
+enable-3pid-lookups