(www/unit) rename patch files for standard naming

diff --git a/unit/patches/patch-ab b/unit/patches/patch-auto_sendfile
similarity index 100%
rename from unit/patches/patch-ab
rename to unit/patches/patch-auto_sendfile

diff --git a/unit/patches/patch-ac b/unit/patches/patch-src_nxt__application.c
similarity index 100%
rename from unit/patches/patch-ac
rename to unit/patches/patch-src_nxt__application.c

diff --git a/unit/patches/patch-aa b/unit/patches/patch-src_nxt__conn__write.c
similarity index 100%
rename from unit/patches/patch-aa
rename to unit/patches/patch-src_nxt__conn__write.c