Let's try to manage without building curl for iOS for now

There was some minor problem in building curl for iOS and I was
feeling lazy and didn't want to bother fixing that. The experimental
LibreOffice app linked fine without curl.

Change-Id: I9ed1fb814bf8b6c4e2a01a58812face68ae2fb68

configure.ac

@@ -8667,6 +8667,9 @@ if test "$with_system_curl" = "yes"; then
     libo_MINGW_TRY_DLL([libgpg-error])
     libo_MINGW_TRY_DLL([libgcrypt])
     libo_MINGW_TRY_DLL([libssh2])
+elif test $_os = iOS; then
+    # Let's see if we need curl, I think not?
+    AC_MSG_RESULT([none])
 else
     AC_MSG_RESULT([internal])
     SYSTEM_CURL=NO