checksrc: find bad indentation in conditions without open brace

If the previous line starts with if/while/for AND ends with a closed
parenthesis and there's an equal number of open and closed parentheses
on that line, verify that this line is indented $indent more steps, if
not a cpp line.

Also adjust the fall-out from this fix.

Closes #11054

lib/imap.c

@@ -1931,7 +1931,7 @@ static CURLcode imap_parse_url_options(struct connectdata *conn)
     const char *value;
 
     while(*ptr && *ptr != '=')
-        ptr++;
+      ptr++;
 
     value = ptr + 1;