Don't leave falsey values out of dict_to_params, let caller do it.

Explicit is better than implicit and all that.

frontends/etiquette_flask/backend/endpoints/photo_endpoints.py

@@ -425,7 +425,9 @@ def get_search_core():
 
     if offset > 0:
         prev_params = original_params.copy()
-        prev_params['offset'] = max(0, offset - limit)
+        prev_offset = max(0, offset - limit)
+        if prev_offset > 0:
+            prev_params['offset'] = prev_offset
         prev_params = helpers.dict_to_params(prev_params)
         prev_page_url = '/search' + prev_params
     else:

frontends/etiquette_flask/backend/helpers.py

@@ -7,9 +7,8 @@ def dict_to_params(d):
     if not d:
         return ''
 
-    params = [f'{key}={value}' for (key, value) in d.items() if value]
+    params = [f'{key}={value}' for (key, value) in d.items()]
     params = '&'.join(params)
-    if params:
-        params = '?' + params
+    params = '?' + params
 
     return params