Fix wrong report for "public slots"

based on google/styleguide#30
original patch by [email protected]

Source code:

class X : public QObject {
...
 public slots:
...
}

causes incorrectly message "Weird number of spaces at line-start.  Are you
using a 2-space indent?  [whitespace/indent] [3]".

cpplint.py

@@ -4439,7 +4439,7 @@ def CheckStyle(filename, clean_lines, linenum, file_extension, nesting_state,
   # if(match($0, " <<")) complain = 0;
   # if(match(prev, " +for \\(")) complain = 0;
   # if(prevodd && match(prevprev, " +for \\(")) complain = 0;
-  scope_or_label_pattern = r'\s*\w+\s*:\s*\\?$'
+  scope_or_label_pattern = r'\s*\w+\s*\w*:\s*\\?$'
   classinfo = nesting_state.InnermostClass()
   initial_spaces = 0
   cleansed_line = clean_lines.elided[linenum]