Fix spelling (#2498)

context.go

@@ -973,7 +973,7 @@ func (c *Context) File(filepath string) {
 	http.ServeFile(c.Writer, c.Request, filepath)
 }
 
-// FileFromFS writes the specified file from http.FileSytem into the body stream in an efficient way.
+// FileFromFS writes the specified file from http.FileSystem into the body stream in an efficient way.
 func (c *Context) FileFromFS(filepath string, fs http.FileSystem) {
 	defer func(old string) {
 		c.Request.URL.Path = old