nginx.org currently provide binaries for opensuse 12.1 and sles 12
The instructions here are for SLES 12, but here they are repeated and modified for opensuse 12.1
sudo zypper addrepo -G -t yum -c 'http://nginx.org/packages/mainline/opensuse/12.1' nginx
sudo zypper in nginx
Or you can add opensuse build binaries.
But in your question you ask about SLES 11, but I saw that you were installing opensuse12.1 src packages. This is a cause of your problem, you cannot do this, or if you can it's the wrong way SLES != opensuse, but also if you are using open use, you'd prefer opensuse 11 for SLES 11.
Goto to
https://software.opensuse.org/package/nginx
Click on the version of SLES 11 you are using, if it's SP4 then the main repo 'server:http' is not configured. If you are on SP3 then clicking on https://build.opensuse.org/package/show?project=server%3Ahttp&package=nginx shows that even though SP3 is configured it isn't currently building as GeoIP is unresolved.
But you want the legacy version of nginx 1.4.7, rather than the current stable 1.8.0
You can look through the builds and see if you can find a matching SLES 11 SPx and nginx version you want.
Then I would add it as a repo, here's how I added nginx to SLES 12 (note osb_suse_servers_http
is just the name I use for the repo)
sudo zypper ar http://download.opensuse.org/repositories/server:/http/SLE_12 osb_suse_servers_http
sudo zypper in nginx