Fix some Clang -Wunused-but-set-variable warnings

(cherry picked from commit e771804e78)

editor/editor_properties.cpp

@@ -697,7 +697,6 @@ public:
 				const int vofs = (grid_size.height - h) / 2;
 
 				int layer_index = 0;
-				int block_index = 0;
 
 				Point2 arrow_pos;
 
@@ -769,8 +768,6 @@ public:
 							break;
 						}
 					}
-
-					++block_index;
 				}
 
 				if ((expansion_rows != prev_expansion_rows) && expanded) {

editor/project_manager.cpp

@@ -526,7 +526,6 @@ private:
 
 					Vector<String> failed_files;
 
-					int idx = 0;
 					while (ret == UNZ_OK) {
 						//get filename
 						unz_file_info info;
@@ -566,7 +565,6 @@ private:
 							}
 						}
 
-						idx++;
 						ret = unzGoToNextFile(pkg);
 					}
 

editor/script_create_dialog.cpp

@@ -204,18 +204,14 @@ String ScriptCreateDialog::_validate_path(const String &p_path, bool p_file_must
 
 	bool found = false;
 	bool match = false;
-	int index = 0;
 	for (List<String>::Element *E = extensions.front(); E; E = E->next()) {
 		if (E->get().nocasecmp_to(extension) == 0) {
-			//FIXME (?) - changing language this way doesn't update controls, needs rework
-			//language_menu->select(index); // change Language option by extension
 			found = true;
 			if (E->get() == ScriptServer::get_language(language_menu->get_selected())->get_extension()) {
 				match = true;
 			}
 			break;
 		}
-		index++;
 	}
 
 	if (!found) {