feat(httpx): add fallback 3rd party completion loader

Author: scop

completions/.gitignore

@@ -116,6 +116,7 @@
 /host
 /hping
 /hping3
+/_httpx
 /_hugo
 /iceweasel
 /identify

completions/Makefile.am

@@ -640,6 +640,7 @@ CLEANFILES = \
 	host \
 	hping \
 	hping3 \
+	_httpx \
 	_hugo \
 	iceweasel \
 	identify \
@@ -1111,7 +1112,7 @@ symlinks: $(DATA)
 	$(ss) ping \
 		ping4 ping6
 	$(ss) _pipenv \
-		_flask
+		_flask _httpx
 	$(ss) pkg-config \
 		pkgconf
 	$(ss) pkg_delete \