Investigate why generate_breakpad_symbols isn't working on Linux builds

[mbacchi]

Adding verbose to the generate_breakpad_symbols.py script:

--- src/brave/app/linux/BUILD.gn	2018-08-24 17:02:51.565592790 -0400
+++ src/brave/app/linux/BUILD.gn	2018-08-24 17:02:47.369560749 -0400
@@ -53,6 +53,7 @@
     "--binary=$start",
     "--libchromiumcontent-dir=" + rebase_path("//"),
     "--clear",
+    "--verbose",
   ]
 
   deps = [

We see the following output when this is run:

16:04:04 [561/607] ACTION //brave/app/linux:generate_breakpad_symbols(//build/toolchain/linux:clang_x64)
16:04:04 Generating symbols for brave
16:04:04 <type 'exceptions.AttributeError'>
16:04:04 'NoneType' object has no attribute 'group'

The resulting linux symbols zip file is only 350kb.