doc/go1.7.html: start sentence on a new line

Change-Id: Ia1c2ebcd2ccf7b98d89b378633bf4fc435d2364d
Reviewed-on: https://go-review.googlesource.com/25019
Reviewed-by: Brad Fitzpatrick <[email protected]>

Author: aclements

doc/go1.7.html

@@ -479,7 +479,8 @@ <h3 id="runtime">Runtime</h3>
 
 <p>
 The runtime can now return unused memory to the operating system on
-all architectures. In Go 1.6 and earlier, the runtime could not
+all architectures.
+In Go 1.6 and earlier, the runtime could not
 release memory on ARM64, 64-bit PowerPC, or MIPS.
 </p>