Bug #1588217: don't parse "= " as a soft line break in binascii's
a2b_qp() function, instead leave it in the string as quopri.decode()
does.
 (backport from rev. 52765)
diff --git a/Modules/binascii.c b/Modules/binascii.c
index 3b2c8b2..4dee451 100644
--- a/Modules/binascii.c
+++ b/Modules/binascii.c
@@ -1057,8 +1057,7 @@
 			in++;
 			if (in >= datalen) break;
 			/* Soft line breaks */
-			if ((data[in] == '\n') || (data[in] == '\r') ||
-			    (data[in] == ' ') || (data[in] == '\t')) {
+			if ((data[in] == '\n') || (data[in] == '\r')) {
 				if (data[in] != '\n') {
 					while (in < datalen && data[in] != '\n') in++;
 				}