Multi-line ISO-8859-1 formatted "Subject:" in email header causes leading space in group name

[gerryfrancis]

• Operating System (Linux/Mac/Windows/iOS/Android): Android 11.

• Delta Chat Version: 1.42.6.

• Expected behavior: No leading space in a group name.

• Actual behavior: A leading space in a group name, caused by a multi-line ISO-8859-1 formatted "Subject:" in the email header.

• Steps to reproduce the problem: -- Receive an email that contains a header carrying a multi-line ISO-8859-1 formatted "Subject:", e.g.:

Subject:
 =?iso-8859-1?Q?Weihnachten_&_Silvester:_Feiern,_genie=DFen_&_entspannen_i?=
 =?iso-8859-1?Q?nmitten_der_Weing=E4rten?=

(Edit: I have double-checked: No space is added to the end of "Subject:" in the first line.)

• Screenshots:

• Logs: N/A.