PCINT with my arduino UNO says redefinition of 'void __vector_4()'
__vector_4() is just another name for PCINT1_vect(). The error
message simply means that you have defined that function twice. One
definition is explicit in the code you are showing to us. I cannot see
the other definition: obviously you are not showing all of your
code. Most likely that other definition lies inside some library you are
using in your program.

Since you cannot define an ISR twice, you will have to use another PCINT
which is not already in use. Or you could modify the library and try to
merge it's PCINT1_vect() with yours.

BTW, the error message does not come from avrdude, it comes from the
linker.