coresendmsg setting link lost rate = 100% causing the link disappear from GUI

```
What steps will reproduce the problem?
1.Start core-daemon and core-gui, add two routers n1 and n2 connected through a
host n3 in between. Start emulation.
2.Issue a coresendmsg command to set the n1 to n3 link lost rate = 100%:
coresendmsg -a 172.16.0.254 link n1number=1 n2number=3 per=100
Watch the link between n1 and n3 disappear from GUI.
3.Issue another coresendmsg command to set the n1 to n3 link lost rate=0%:
coresendmsg -a 172.16.0.254 link n1number=1 n2number=3 per=0
Watch the following respond to the coresendmsg command:
link modify message received, but no wired link or wlan for nodes n1-n3, dropping

What is the expected output? What do you see instead?
setting link lost rate will not cause the link deleted.

What version of the product are you using? On what operating system?
CORE 4.7, core svn 1975

Please provide any additional information below.
See file attached.

```

Original issue reported on code.google.com by `yueli.y...@gmail.com` on 10 Mar 2015 at 3:44

Attachments:
- [coreLinkPer100Bug.docx](https://storage.googleapis.com/google-code-attachments/coreemu/issue-279/comment-0/coreLinkPer100Bug.docx)