[fix] categories: rename stock_images category to stock images (#6760)

Category ``stock_images`` is referenced to as ``stock images`` everywhere else,
so SXNG didn't find any translation for ``stock_images``.

searx/engines/500px.py

@@ -33,7 +33,7 @@ about = {
 base_url = "https://500px.com"
 api_url = "https://api-neo.500px.com"
 
-categories = ["stock_images"]
+categories = ["stock images"]
 paging = True
 
 results_per_page = 30

searx/engines/flickr.py

@@ -18,7 +18,7 @@ about = {
     "results": 'JSON',
 }
 
-categories = ["stock_images"]
+categories = ["stock images"]
 
 page_size = 15
 paging = True

searx/engines/magnific.py

@@ -31,7 +31,7 @@ about = {
 
 base_url = "https://www.magnific.com"
 
-categories = ["stock_images"]
+categories = ["stock images"]
 paging = True
 
 free_images_only = True

searx/engines/pexels.py

@@ -26,7 +26,7 @@ about = {
 }
 
 base_url = "https://www.pexels.com"
-categories = ["stock_images"]
+categories = ["stock images"]
 
 api_key = "H2jk9uKnhRmL6WPwh89zBezWvr"
 """

searx/engines/picjumbo.py

@@ -26,7 +26,7 @@ about = {
 
 base_url = "https://picjumbo.com"
 
-categories = ["stock_images"]
+categories = ["stock images"]
 paging = True
 
 

searx/engines/shopify_stock.py

@@ -25,7 +25,7 @@ about = {
 
 base_url = "https://www.shopify.com"
 
-categories = ["stock_images"]
+categories = ["stock images"]
 paging = True
 
 

searx/engines/stocksnap.py

@@ -25,7 +25,7 @@ about = {
 base_url = "https://stocksnap.io"
 cdn_url = "https://cdn.stocksnap.io"
 
-categories = ["stock_images"]
+categories = ["stock images"]
 paging = True
 
 

searx/engines/unsplash.py

@@ -18,7 +18,7 @@ about = {
 
 base_url = 'https://unsplash.com/'
 search_url = base_url + 'napi/search/photos?'
-categories = ["stock_images"]
+categories = ["stock images"]
 page_size = 20
 paging = True
 

searx/engines/www1x.py

@@ -17,7 +17,7 @@ about = {
 }
 
 # engine dependent config
-categories = ["stock_images"]
+categories = ["stock images"]
 paging = False
 
 # search-url

searx/settings.yml

@@ -280,7 +280,7 @@ plugins:
 categories_as_tabs:
   general:
   images:
-  # stock_images:
+  # stock images:
   videos:
   news:
   map:
@@ -1932,7 +1932,7 @@ engines:
   - name: pixabay images
     engine: pixabay
     pixabay_type: images
-    categories: stock_images
+    categories: stock images
     shortcut: pixi
     disabled: true