Increase maximum global speed limits from ~1 GiB/s to ~2 GiB/s

Closer to the INT_MAX limit of ~2 Billion when multiplied by 1024 for libtorrent

src/gui/optionsdialog.ui

@@ -1866,7 +1866,7 @@ Manual: Various torrent properties (e.g. save path) must be assigned manually</s
                   <string> KiB/s</string>
                  </property>
                  <property name="maximum">
-                  <number>1000000</number>
+                  <number>2000000</number>
                  </property>
                  <property name="value">
                   <number>100</number>
@@ -1882,7 +1882,7 @@ Manual: Various torrent properties (e.g. save path) must be assigned manually</s
                   <string> KiB/s</string>
                  </property>
                  <property name="maximum">
-                  <number>1000000</number>
+                  <number>2000000</number>
                  </property>
                  <property name="value">
                   <number>100</number>
@@ -1937,7 +1937,7 @@ Manual: Various torrent properties (e.g. save path) must be assigned manually</s
                   <string> KiB/s</string>
                  </property>
                  <property name="maximum">
-                  <number>1000000</number>
+                  <number>2000000</number>
                  </property>
                  <property name="value">
                   <number>10</number>
@@ -2073,7 +2073,7 @@ Manual: Various torrent properties (e.g. save path) must be assigned manually</s
                   <string> KiB/s</string>
                  </property>
                  <property name="maximum">
-                  <number>1000000</number>
+                  <number>2000000</number>
                  </property>
                  <property name="value">
                   <number>10</number>