Fix eclipse project generation

Since I44411dbee, generation of eclipse was not working, i.e. the source
folders were not included in the eclipse project.

I44411dbee reverted a fix done by Ib50d37c12 and I3bd95c1c6.

Change-Id: I1de328d8f491909c1fa391f8d218510c23508ad4
diff --git a/tools/eclipse.py b/tools/eclipse.py
index 2d62759..25fe28c 100755
--- a/tools/eclipse.py
+++ b/tools/eclipse.py
@@ -87,11 +87,11 @@
   src = set()
   lib = set()
 
-  java_library = re.compile(r'[^/]+/gen/(.*)/lib__[^/]+__output/[^/]+[.]jar$')
+  java_library = re.compile(r'[^/]+/gen(.*)/lib__[^/]+__output/[^/]+[.]jar$')
   for p in _query_classpath(MAIN):
     m = java_library.match(p)
     if m:
-      src.add(m.group(1))
+      src.add(m.group(1).lstrip('/'))
     else:
       lib.add(p)