Added icat to .gitignore

.gitignore

diff --git a/.gitignore b/.gitignore
index 6c0a8c9..f925abd 100644
--- a/.gitignore
+++ b/.gitignore
@@ -37,3 +37,4 @@
 libusbmuxd.pc
 tools/.libs/*
 tools/iproxy
+tools/icat