Spell info window, text should be adjusted when the hero has zero ("0") mana

[LeHerosInconnu]

Preliminary checks

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Describe the problem requiring a solution

In fheroes2, the text should be adjusted when the hero has zero ("0") mana.

In fheroes2 (with "Town Portal" spell):

Describe the possible solution

It could be:

"You have 0 mana, ..."

Or:

"You have no mana, ..."

Instead of:

"You only have 0 mana, ..."

Additional info

Version 0.9.13 5171