Regression since 20f6cd595c
The early code might meet bridge is empty when
there is no bridge(e.x. rtc to rtc). Then srs_freep will free the brige.
Remove this code that seems redundant.
---------
Co-authored-by: Jacob Su <suzp1984@gmail.com>
Signed-off-by: Jack Lau <jacklau1222@qq.com>