zsh:autosuggestions: Switch to history strategy

I don't feel as if I'm actively benefiting from match_prev_cmd and it
definitely makes my prompt slower. (One could probably make it faster by
pre-calculating the history events matching the (previously) executed
command in a preexec zsh-hook and then comparing each successor to the
currently typed command instead of repeating all the work every time
BUFFER changes)

With this change my fork is not needed anymore, so switch back to
zsh-users' repo and update it while at it.

This effectively reverts 77b2d63341 ("zsh:autosuggestions: Use own
fork for now").

.gitmodules

@@ -126,7 +126,7 @@
 	url = https://github.com/sickill/stderred
 [submodule "zsh-autosuggestions"]
 	path = .local/share/zsh/plugins/zsh-autosuggestions
-	url = https://github.com/druckdev/zsh-autosuggestions
+	url = https://github.com/zsh-users/zsh-autosuggestions
 [submodule "zsh-syntax-highlighting"]
 	path = .local/share/zsh/plugins/zsh-syntax-highlighting
 	url = https://github.com/zsh-users/zsh-syntax-highlighting