Tweak some authentication debug messages to follow project style.

Avoid initial capital, since that's not how we do it.

Discussion: https://postgr.es/m/CACP=ajbrFFYUrLyJBLV8=q+eNCapa1xDEyvXhMoYrNphs-xqPw@mail.gmail.com

src/backend/libpq/auth.c

@@ -960,7 +960,7 @@ CheckSCRAMAuth(Port *port, char *shadow_pass, char **logdetail)
 			return STATUS_ERROR;
 		}
 
-		elog(DEBUG4, "Processing received SASL response of length %d", buf.len);
+		elog(DEBUG4, "processing received SASL response of length %d", buf.len);
 
 		/*
 		 * The first SASLInitialResponse message is different from the others.
@@ -1151,7 +1151,7 @@ pg_GSS_recvauth(Port *port)
 		gbuf.length = buf.len;
 		gbuf.value = buf.data;
 
-		elog(DEBUG4, "Processing received GSS token of length %u",
+		elog(DEBUG4, "processing received GSS token of length %u",
 			 (unsigned int) gbuf.length);
 
 		maj_stat = gss_accept_sec_context(
@@ -1428,8 +1428,7 @@ pg_SSPI_recvauth(Port *port)
 		outbuf.pBuffers = OutBuffers;
 		outbuf.ulVersion = SECBUFFER_VERSION;
 
-
-		elog(DEBUG4, "Processing received SSPI token of length %u",
+		elog(DEBUG4, "processing received SSPI token of length %u",
 			 (unsigned int) buf.len);
 
 		r = AcceptSecurityContext(&sspicred,
@@ -2957,7 +2956,7 @@ radius_add_attribute(radius_packet *packet, uint8 type, const unsigned char *dat
 		 * fail.
 		 */
 		elog(WARNING,
-			 "Adding attribute code %d with length %d to radius packet would create oversize packet, ignoring",
+			 "adding attribute code %d with length %d to radius packet would create oversize packet, ignoring",
 			 type, len);
 		return;
 	}