doc: remove duplicate python packages, explicitly ensure python scrip…

…t installation in path /usr/bin.

Signed-off-by: Stefan Kooman <stefan@kooman.org>

doc/rbd/iscsi-target-cli-manual-install.rst

@@ -126,7 +126,7 @@ on each machine that will be a iSCSI gateway:
 
        > git clone https://github.com/ceph/ceph-iscsi-config.git
        > cd ceph-iscsi-config
-       > python setup.py install
+       > python setup.py install --install-scripts=/usr/bin
        > cp usr/lib/systemd/system/rbd-target-gw.service /lib/systemd/system
 
    Enable and start the daemon:
@@ -145,7 +145,7 @@ on each machine that will be a iSCSI gateway:
 
        > git clone https://github.com/ceph/ceph-iscsi-cli.git
        > cd ceph-iscsi-cli
-       > python setup.py install
+       > python setup.py install --install-scripts=/usr/bin
        > cp usr/lib/systemd/system/rbd-target-api.service /lib/systemd/system