For each of those pseudobonds, there is a hidden “real” bond. To have the Mol2 file treat the segments as disconnected, the hidden bonds have to be deleted. I have attached a simple Python script that does that. So you would open your PDB file, run the script (simply opening the .py file will run it) and then save your Mol2.

Keep in mind that deleting those hidden bonds will change the corresponding atom types. So for instance the backbone nitrogens will be given the Mol2 type N.4 (appropriate for N-terminal) rather than N.am (appropriate for amide).