srm+https not correctly stripped (related #4513)
It is necessary to changes `srm+https://...` scheme to `srm://...` before passing this URL to gfal, but current code remove too many characters and as a result we get `srm//...` without `:`

https://github.com/rucio/rucio/blob/f1159fbf1e6002715a77b613d35d037c55082803/lib/rucio/core/transfer.py#L685
https://github.com/rucio/rucio/blob/f1159fbf1e6002715a77b613d35d037c55082803/lib/rucio/core/transfer.py#L701

diff --git a/lib/rucio/core/transfer.py b/lib/rucio/core/transfer.py
index 520edd4e5..027195be1 100644
--- a/lib/rucio/core/transfer.py
+++ b/lib/rucio/core/transfer.py
@@ -682,7 +682,7 @@ def __rewrite_source_url(source_url, source_sign_url, dest_sign_url, source_sche
             source_url = source_sign_url_map[source_sign_url] + source_url[5:]
 
     if source_url[:12] == 'srm+https://':
-        source_url = 'srm' + source_url[10:]
+        source_url = 'srm' + source_url[9:]
     return source_url
 
 
@@ -698,7 +698,7 @@ def __rewrite_dest_url(dest_url, dest_sign_url, dest_scheme):
         dest_url = re.sub('https', 's3s', dest_url)
 
     if dest_url[:12] == 'srm+https://':
-        dest_url = 'srm' + dest_url[10:]
+        dest_url = 'srm' + dest_url[9:]
     return dest_url
 
 
['lib/rucio/core/transfer.py']