I found out what to do. I need to reset the configuration file by inserting this code into beginning of the program

#config
__config _mclre_off
#endconfig

The pin 4 (bit 3) will now be an INPUT with an internal pull-up resistor.

NOTE: The underline before the config is a double underline __ and not a single underline_

There is a space after the config and before the _mclre


Thank you, Henrik, for your response.