Fixes failed canvas generation when gallery is empty

There was some old logic from before Unified Canvas which aborted generation when there was no currentImage. 

If you have an image in the gallery, there is always a currentImage. But if gallery is empty, there is no currentImage. Generation would silently fail in this case.

We apparently never tested with an empty gallery and thus never ran into the issue. This removes this old and now-unused logic.

frontend/dist/index.html

@@ -6,7 +6,7 @@
   <meta name="viewport" content="width=device-width, initial-scale=1.0" />
   <title>InvokeAI - A Stable Diffusion Toolkit</title>
   <link rel="shortcut icon" type="icon" href="./assets/favicon.0d253ced.ico" />
-  <script type="module" crossorigin src="./assets/index.bd109a2c.js"></script>
+  <script type="module" crossorigin src="./assets/index.637f12bd.js"></script>
   <link rel="stylesheet" href="./assets/index.c609c0c8.css">
 </head>
 

frontend/src/app/socketio/emitters.ts

@@ -42,7 +42,6 @@ const makeSocketIOEmitters = (
         options: optionsState,
         system: systemState,
         canvas: canvasState,
-        gallery: galleryState,
       } = state;
 
       const frontendToBackendParametersConfig: FrontendToBackendParametersConfig =
@@ -55,13 +54,6 @@ const makeSocketIOEmitters = (
 
       dispatch(generationRequested());
 
-      if (!['txt2img', 'img2img'].includes(generationMode)) {
-        if (!galleryState.currentImage?.url) return;
-
-        frontendToBackendParametersConfig.imageToProcessUrl =
-          galleryState.currentImage.url;
-      }
-
       const { generationParameters, esrganParameters, facetoolParameters } =
         frontendToBackendParameters(frontendToBackendParametersConfig);
 

frontend/src/common/util/parameterTranslation.ts

@@ -30,13 +30,7 @@ export const frontendToBackendParameters = (
 ): { [key: string]: any } => {
   const canvasBaseLayer = getCanvasBaseLayer();
 
-  const {
+  const { generationMode, optionsState, canvasState, systemState } = config;
-    generationMode,
-    optionsState,
-    canvasState,
-    systemState,
-    imageToProcessUrl,
-  } = config;
 
   const {
     cfgScale,
@@ -164,7 +158,6 @@ export const frontendToBackendParameters = (
 
     generationParameters.fit = false;
 
-    generationParameters.init_img = imageToProcessUrl;
     generationParameters.strength = img2imgStrength;
 
     generationParameters.invert_mask = shouldPreserveMaskedArea;