chore(deps): update github.com/piranha/gostatic commit hash to 51f6075

This MR contains the following updates:

Package	Type	Update	Change
github.com/piranha/gostatic	require	digest	a5be161 -> 51f6075

---

Renovate configuration

Schedule: At any time (no schedule defined).

Automerge: Disabled by config. Please merge this manually once you are satisfied.

️ Rebasing: Whenever MR becomes conflicted, or you tick the rebase/retry checkbox.

Ignore: Close this MR and you won't be reminded about this update again.

---

• If you want to rebase/retry this MR, check this box

---

This MR has been generated by Renovate Bot.

go.mod

@@ -15,13 +15,12 @@ require (
 	github.com/golang/snappy v0.0.0-20180518054509-2e65f85255db // indirect
 	github.com/mschoch/smat v0.1.0 // indirect
 	github.com/philhofer/fwd v1.0.0 // indirect
-	github.com/piranha/gostatic v0.0.0-20161004053103-a5be16164c57
+	github.com/piranha/gostatic v0.0.0-20210209094842-51f60750f05e
 	github.com/russross/blackfriday v0.0.0-20161003162722-5f33e7b78783
 	github.com/shurcooL/sanitized_anchor_name v0.0.0-20160918041101-1dba4b3954bc // indirect
 	github.com/steveyen/gtreap v0.0.0-20150807155958-0abe01ef9be2 // indirect
 	github.com/tinylib/msgp v1.0.3-0.20180912221530-f65876d3ea05 // indirect
 	github.com/willf/bitset v1.1.4-0.20170905002639-1a37ad96e8c1 // indirect
-	golang.org/x/sys v0.0.0-20161016222106-002cbb5f9524 // indirect
-	golang.org/x/text v0.0.0-20161003125028-098f51fb687d
+	golang.org/x/text v0.3.0
 	gopkg.in/fsnotify.v1 v1.4.2 // indirect
 )