Simplify; apply editorconfig for *.bzl

Author: ash2k

.editorconfig

@@ -13,7 +13,7 @@ insert_final_newline = true
 indent_style = space
 indent_size = 2
 
-[BUILD.bazel]
+[{BUILD.bazel,*.bzl}]
 insert_final_newline = true
 indent_style = space
 indent_size = 4

buildozer/def.bzl

@@ -14,9 +14,9 @@ def _buildozer_impl(ctx):
         "-delete_with_comments=%s" % str(ctx.attr.delete_with_comments).lower(),
     ]
     if ctx.file.tables:
-        args.extend(["-tables=%s" % ctx.file.tables.short_path])
+        args.append("-tables=%s" % ctx.file.tables.short_path)
     if ctx.file.add_tables:
-        args.extend(["-add_tables=%s" % ctx.file.add_tables.short_path])
+        args.append("-add_tables=%s" % ctx.file.add_tables.short_path)
 
     out_file = ctx.actions.declare_file(ctx.label.name + ".bash")
     substitutions = {