An Ethiopian Sparrow
Actually called: Brown-Rumped Seedeater (Crithagra tristriata)
[Photo By: KPA]
A plain seedeater of the Abyssinian highlands. Note the gray-brown back, the paler underparts, the white eyebrow, and the small white throat. Generally common in a variety of montane habitats including forest edge, woodland, scrub, and gardens. Similar in overall coloration to Reichard’s and Streaky Seedeaters, but easily separated by the plain unstreaked underparts. The simple song consists of repeated scratchy whistles. [Source]
More here.
This little bird was busy collecting small twigs and straw (dried grass) for a nest. It didn't seemed very alarmed by my presence, and is probably used to being around people.