Fix fail message construction in cc_shared_library
Previously, if there were many unaccounted for libraries, this would simply fail with:
```
Error in join: 'string' is not iterable
```
Closes
@@ -359,7 +359,7 @@ def _throw_error_if_unaccounted_libs(unaccounted_for_libs):
libs_message.append(str(unaccounted_lib))
if len(unaccounted_for_libs) > 10:
- libs_message = "(and " + str(len(unaccounted_for_libs) - 10) + " others)\n"
+ libs_message.append("(and " + str(len(unaccounted_for_libs) - 10) + " others)\n")
static_deps_message = []
for repo in different_repos:
