Fix k_diffusion math being off by a tiny bit during txt2img.

comfy/samplers.py

@@ -650,6 +650,9 @@ class KSampler:
                 self.model_k.latent_image = latent_image
                 self.model_k.noise = noise
 
+                if max_denoise:
+                    noise = noise * torch.sqrt(1.0 + sigmas[0] ** 2.0)
+                else:
                     noise = noise * sigmas[0]
 
                 k_callback = None