Ignore adb/*.pyc files

Python scripts in system/core/ such as perfboot.py may generate
the files.

Change-Id: I0506d47db414a678f1923e747ddce5acfcd7ce1b
diff --git a/.gitignore b/.gitignore
index b25c15b..2f836aa 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 *~
+*.pyc