Fix AttributeError in OFT when trying to get MultiheadAttention weight

[v0xie]

Description

We avoid an AttributeError by changing the condition from if self.rescale is not None: to if self.rescale is not None and not is_other_linear:.

Related: #15190

Screenshots/videos:

Traceback (most recent call last):
  File "F:\stablediffusion\stable-diffusion-webui\extensions-builtin\Lora\networks.py", line 280, in load_networks
    net = load_network(name, network_on_disk)
  File "F:\stablediffusion\stable-diffusion-webui\extensions-builtin\Lora\networks.py", line 219, in load_network
    net_module = nettype.create_module(net, weights)
  File "F:\stablediffusion\stable-diffusion-webui\extensions-builtin\Lora\network_oft.py", line 9, in create_module
    return NetworkModuleOFT(net, weights)
  File "F:\stablediffusion\stable-diffusion-webui\extensions-builtin\Lora\network_oft.py", line 44, in __init__
    self.rescale = self.rescale.reshape(-1, *[1]*(self.org_module[0].weight.dim() - 1))
  File "f:\stablediffusion\stable-diffusion-webui\venv\lib\site-packages\torch\nn\modules\module.py", line 1695, in __getattr__
    raise AttributeError(f"'{type(self).__name__}' object has no attribute '{name}'")
AttributeError: 'MultiheadAttention' object has no attribute 'weight'

Checklist:

• I have read contributing wiki page
• I have performed a self-review of my own code
• My code follows the style guidelines
• My code passes tests