include imaginary axis in right half-plane for Γ(z)

Author: banana-bred

src/stdlib_specialfunctions_gamma.fypp

@@ -298,14 +298,14 @@ contains
 
         end if
 
-        if(z % re > zero_k1) then
+        if(z % re < zero_k1) then
 
-            y = z - one
+            x = cmplx(abs(z % re), - z % im, kind = ${k1}$)
+            y = x - one
 
         else
 
-            x = cmplx(abs(z % re), - z % im, kind = ${k1}$)
-            y = x - one
+            y = z - one
 
         end if