All of the following packages depend on libcurl4:
root@vuduo:~# opkg whatdepends -A libcurl4
Root set:
libcurl4
What depends on root set
rtorrent 0.9.2-r0 depends on libcurl4 (>= 7.32.0)
gst-plugins-bad-curl 0.10.23.1+git12245+fb0d870-r3 depends on libcurl4 (>= 7.32.0)
mpd 0.15.9-r2 depends on libcurl4 (>= 7.19.7)
libcurl-dev 7.32.0-r0 depends on libcurl4
enigma2-plugin-extensions-transmission 2.60 depends on libcurl4 (>= 7.19.7)
curl 7.32.0-r0 depends on libcurl4 (>= 7.32.0)
enigma2-plugin-extensions-buyukbangpanel 1.3.2-r0 depends on libcurl4
rtorrent-dev 0.9.2-r0 depends on rtorrent (= 0.9.2-r0)
python-pycurl 7.19.0-r3 depends on libcurl4 (>= 7.32.0)
curl-dev 7.32.0-r0 depends on curl (= 7.32.0-r0)
transmission-client 2.73-r1.1 depends on libcurl4 (>= 7.32.0)
transmission 2.73-r1.1 depends on libcurl4 (>= 7.32.0)
So, here is a work-around until it is fixed:
root@vuduo:~# opkg install librtmp1
root@vuduo:~# ln -sv librtmp.so.1 /usr/lib/librtmp.so.0
root@vuduo:~# opkg install --force-depends libcurl4
Now you can install any of the above packages...