fix: use real part of irfft output

Author: IanButterworth

src/imfilter.jl

@@ -874,8 +874,7 @@ end
 function filtfft(A, krn, planned_rfft1::Function, planned_rfft2::Function, planned_irfft::Function)
     B = planned_rfft1(A)
     complex(B) .*= conj!(complex(planned_rfft2(krn)))
-    out = complex(planned_irfft(complex(B)))
-    return out
+    return real(planned_irfft(complex(B)))
 end
 filtfft(A, krn, ::Nothing, ::Nothing, ::Nothing) = filtfft(A, krn)
 function filtfft(A, krn)