White line on my Puma

Hi guys, I bought Puma Caven 2.0 Year of Sport and its been just 20 days. Today I noticed a white line at the front part of it (see attached pic). Can anyone help me with this and tell me what is it? I have been wearing it everyday since last 20 days and have to cleaned them yet.

Hi guys, I bought Puma Caven 2.0 Year of Sport and its been just 20 days. Today I noticed a white line at the front part of it (see attached pic). Can anyone help me with this and tell me what is it? I have been wearing it everyday since last 20 days and have to cleaned them yet.