fix(bootloader_support): check the secure version only for app image

Secure version in the image header is only available for the application
image. However, for certain security workflows, bootloader verifies
itself (own image) and hence the secure version check during that must be
avoided.

Regression introduced in recent commit-id: 3305cb4

Tested that both secure boot and flash-enc workflows work correctly
with the anti-rollback scenario.

components/bootloader_support/src/esp_image_format.c

@@ -688,12 +688,16 @@ static esp_err_t process_segment_data(int segment, intptr_t load_addr, uint32_t
 #endif
     }
     uint32_t *dest = (uint32_t *)load_addr;
-#endif
+#endif // BOOTLOADER_BUILD
 
     const uint32_t *src = data;
 
 #if CONFIG_BOOTLOADER_APP_ANTI_ROLLBACK
-    if (segment == 0) {
+    // Case I: Bootloader verifying application
+    // Case II: Bootloader verifying bootloader
+    // Anti-rollback check should handle only Case I from above.
+    if (segment == 0 && metadata->start_addr != ESP_BOOTLOADER_OFFSET) {
+        ESP_LOGD(TAG, "additional anti-rollback check 0x%"PRIx32, data_addr);
         // The esp_app_desc_t structure is located in DROM and is always in segment #0.
         size_t len = process_esp_app_desc_data(src, sha_handle, checksum, metadata);
         data_len -= len;