Add not found header after postprocessing

The postprocessing method assumes that the sout data is always delivered in the same format. If the location is not found, the passed format deviates and this then leads to an incorrect behavior => incorrect return value.
Close #729
Close #728

lib/view/wttr.py

@@ -31,6 +31,7 @@ def get_wetter(parsed_query):
     returncode = 0
     if not location_not_found:
         stdout, stderr, returncode = _wego_wrapper(location, parsed_query)
+        first_line, stdout = _wego_postprocessing(location, parsed_query, stdout)
 
     if location_not_found or \
         (returncode != 0 \
@@ -57,13 +58,8 @@ def get_wetter(parsed_query):
         not_found_footer = "\n".join("\033[48;5;91m " + x + " \033[0m"
                                      for x in not_found_footer.splitlines() if x) + "\n"
 
-        stdout = not_found_header + "\n----\n" + stdout + not_found_footer
-
-    if "\n" in stdout:
         first_line, stdout = _wego_postprocessing(location, parsed_query, stdout)
-    else:
+        stdout = not_found_header + "\n----\n" + stdout + not_found_footer
-        first_line = ""
-
 
     if html:
         return _htmlize(stdout, first_line, parsed_query)