In short, De Sales and Ott are talking about two distinct words.
"Church" in English comes through OE circe from Proto-Germanic *kirika, thought to come through non-Latin etymologies from Greek kyriake "The Lord's (house)", as etymonline has it. Ott is German; he is writing about a word that is derived from Gr. κυριακόν.
In Latin, however, ecclesia was often used, which comes from a Greek word derived eventually from kalein ("to call"). "Ecclesiastes" and "Ecclesiastic" come from this Latin word. De Sales wrote in French, using the word église (which is derived from the Latin ecclesia, and before this from Gr. ἐκκλησία); all three are usually translated church in Engish:
L'Eglise vient d'un mot grec , qui veut dire convocation : l'Eglise donc signifie une assemblée, ou une compaignie rie gens appeliez; la Synagogue, à proprement parler, veut dire un trouppeau... Controverses on Google books
Ott, unsurprisingly, wrote about the english word derived from the Germanic Kirche.
The Greek used the word ἐκκλησία quite some time before Christ's promise as recorded in Mt 16:18 ("...I will build my church"), the first use of this word in the Bible. The Greek Ecclesia was a sort of voting body, a "citizen's assembly" if you will. Brittanica, for example, says that it meant
(“gathering of those summoned”), in ancient Greece, assembly of citizens in a city-state. Its roots lay in the Homeric agora, the meeting of the people.
And with regard to the historical use of this word,
The Athenian Ecclesia, for which exists the most detailed record, was already functioning in Draco’s day (c. 621 bc).
Etymologically, Greek ecclesia is
a compound of two segments: "ek", a preposition meaning "out of", and a verb, "kaleo", signifying "to call" - together, literally, "to call out". That usage soon disappeared and was replaced with "assembly, congregation, council", or "convocation". wikipedia
The Germanics, on the other hand, did not use an ecclesia-derived word; their whole geographical region used words derived from Proto-Germanic kirika, again according to etymonline:
This is probably [see extensive note in OED] borrowed via an unrecorded Gothic word from Greek kyriake (oikia), kyriakon doma "the Lord's (house)," from kyrios "ruler, lord," from PIE root *keue- "to swell" ("swollen," hence "strong, powerful").
Greek kyriakon (adj.) "of the Lord" was used of houses of Christian worship since c. 300, especially in the East, though it was less common in this sense than ekklesia or basilike. An example of the direct Greek-to-Germanic transmission of many Christian words, via the Goths; probably it was used by West Germanic people in their pre-Christian period.