ffmpeg: openssl fix

When OpenSSL is used as an option, it currently taps the system
OpenSSL. This fixes that by adding an optional dependency to our
OpenSSL.

Closes #34136.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>

Library/Formula/ffmpeg.rb

@@ -33,7 +33,7 @@ class Ffmpeg < Formula
 
   depends_on "pkg-config" => :build
 
-  # manpages won"t be built without texi2html
+  # manpages won't be built without texi2html
   depends_on "texi2html" => :build if MacOS.version >= :mountain_lion
   depends_on "yasm" => :build
 
@@ -62,6 +62,7 @@ class Ffmpeg < Formula
   depends_on "libquvi" => :optional
   depends_on "libvidstab" => :optional
   depends_on "x265" => :optional
+  depends_on "openssl" => :optional
 
   def install
     args = ["--prefix=#{prefix}",