mime: add .jpeg for builtin

Change-Id: I32b0c02039d8baca1358dac2cc0afd14fa6cd173
GitHub-Last-Rev: d3be7aa039fbe94450c54f2c1dc5a510cf183378
GitHub-Pull-Request: golang/go#31232
Reviewed-on: https://go-review.googlesource.com/c/go/+/170657Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

src/mime/type.go

@@ -62,6 +62,7 @@ var builtinTypesLower = map[string]string{
 	".htm":  "text/html; charset=utf-8",
 	".html": "text/html; charset=utf-8",
 	".jpg":  "image/jpeg",
+	".jpeg": "image/jpeg",
 	".js":   "application/javascript",
 	".wasm": "application/wasm",
 	".pdf":  "application/pdf",